Id say around 80% since I use a lot of foss programs and only use linux/android/openwrt/brother printers. The other 20% is random proprietary stuff like steam I guess to be generous.
All my computers run Linux exclusively. Gaming desktop, personal laptop, Steam Deck, work laptop, and all my servers in my home lab.
Hypervisor is XCP-ng, VMs are a mix of Ubuntu, Debian, Fedora, and some random other Linux distros for testing and experimenting.
My NAS is a TrueNAS Core box.
I'm in the process of switching my router to PFSense.
Phone is a Pixel 6a with GrapheneOS.
Email, VPN, and cloud storage is Proton.
Password manager is Bit Warden.
Office docs are all Libre Office & Only Office.
The only non-FOSS software I use constantly is Discord and Steam, and of course, most of the games I play. On my phone I have majority FOSS apps for everyday stuff, but some things are still proprietary.
A good 90% I'd say. All my devices run Linux (NixOS laptop, Ubuntu server, LineageOS phone).
Non-FOSS stuff:
AMD GPU in my Framework 16 laptop means the only unfree package on my laptop is Steam.
The proprietary apps I do run on my phone are TooGoodToGo and my bank as I'm not aware of alternatives.
I wear a Pebble Time Steel smartwatch, also not aware of any alternatives.
PS5 controller firmware has no replacement.
I don't browse the surface web a lot and when I do I tend to disable JS, so I avoid most of the nonfree JS.
I have no social media accounts besides Mastodon, Matrix, and Lemmy, which are all free :)
As an extension, all my close family runs Linux on their computers, as it ended up being lower maintenance than setting them up with Windows when time came to upgrade.
I don't run Linux anymore, though this should change sometime next year. I use Blender and Krita for work, QOwnNotes for note-taking, Firefox for the web, QBittorrent for sharing holiday films, etc. For image editing I use Affinity, probably the only notable proprietary program on my system apart from Windows.
Got multiple machines, but I think my most FOSS setup is a corebooted Thinkpad X230. The ME firmware was stripped, leaving it non-functional after the initialization. I replaced the WiFi card with an Atheros one that doesn't require non-free firmware. The GPU is by Intel Ivy Bridge, so no need for proprietary driver. Currently running Debian on it.
With that said, there are some components I couldn't get by:
the EC firmware is pretty much a blackbox, even though I was able to unlock some part to make it work with aftermarket batteries
the graphic ROM may still be proprietary (gonna have to recheck what my machine got currently) -- FOSS is an option as well but with less support
even though non-functional, the ME is still on -- god knows what this thing does exactly
CPU microcode
The rest of the components are pretty well-documented by the community if not by the OEMs themselves.
I would put 95% for this specific setup. However, if counting everything I got, not even close, as I need some proprietary components for living.
For example, my company gave me a newer Thinkpad to do work, which thankfully I got to install Linux on. I still have to run enterprise stuff from time to time, most of which are far from FOSS.
Nearly 100%. All Linux and AMD. The biggest part that isn't is BIOS. As far as programs go I can think of almost nothing I use that isn't FOSS. I guess Discord.
I still use services like Spotify, FB Messenger, and Play services for some of my banking apps. I'm a bit new to this whole privacy thing and custom ROMs, but so far it feels good. When I buy a computer I'll install Linux on it.
PC - Thinkpad T14s Gen 4: EndeavourOS, Firefox and Thunderbird with the Proton suite of things such as Mail, Pass and VPN - I do pay for them but I think it's worth it.
Phone - Pixel 8 with GrapheneOS and as many F-Droid apps as possible. Proton apps for Mail, Pass, Drive, VPN. Cromite browser. The only that aren't are probably my banking apps, but I could always switch to web I guess.
I think my biggest hurdle is a Map app that has traffic data that isn't Google maps.
Excluding hardware (microcode, UEFI, etc); within my Linux system, the only proprietary software I have installed are Nvidia drivers and Steam (installed via flatpak).
When I first made the switch to Linux, I was actually shocked at the minimal amount of proprietary software I actually used/needed.
Linux on all my computers and GrapheneOS on my Google Pixel 6a with 99.8% FOSS applications. Maybe 96% FOSS softwares on my stationary computer and 100% on my laptops.
Linux desktop with an Nvidia GPU, two Linux laptops, android phone. I'm struggling to think of any closed source productivity apps I still use, and I play games from Steam. NAS is running whatever Synology crap it came with, I haven't tried fucking with the firmware on my Epson, my 3D printer runs Marlin and my laser engraver runs GRBL.
Home gateway with LibreCMC, Nextcloud and a bunch of services I need, completely free software down to the wireless module firmware. On my computer I use Parabola GNU/Linux-libre modified to load a non free firmware for my graphics card. Being a x86-64 based system, there are non free firmwares in ROMs. I also run proprietary video games in an unprivileged container. Everything else is fully free.
Almost everything. All Linux machines, SO included. Self-hosted most everything for a loooooong time, but with Obtainium now I'm really close to ditching the Play Store, too.
Framework laptop with x86 Intel CPU, running OpenBSD. All drivers are free, non-free firmware includes intel, inteldrm, iwx (intel wireless device), uvideo (webcam), vmm (virtual machine). BIOS/UEFI is closed.
Hopefully intel, inteldrm, and vmm firmware can be removed after I switch to the RISC-V mainboard that is releasing for the Framework 13 inch soon. iwx firmware can be removed as soon as OpenBSD has better atheros drivers, whenever that patch arrives (or whatever other foss wireless card comes along). uvideo firmware might be unnecessary, but I haven't checked.
FOSS score: Medium-Low, after switching mainboard, Good.
Phone
OG Pinephone running postmarketOS. I don't think there's any non-free firmware (GPU maybe?). ARM64 CPU, only closed firmware I know of is the modem, which I've replaced with a free version here. Don't know about the UEFI/BIOS.
FOSS score: Good, Medium if UEFI/BIOS is closed or there is non-free firmware.
Gaming
Steam Deck, x86 AMD cpu, running proprietary SteamOS. May replace the OS at some point if a good alternative comes along, as SteamOS's immutable design and lack of real package manager besides flatpak annoys me.
FOSS score: Terrible, will always be Terrible because of all the games, even after replacing the OS.
I try to use FOSS as much as possible, but I am not willing to give up video games, so I do have steam installed. I also need discord for communication with friends I am playing with. I only use these two on my desktop computer. On my laptop I don't have any proprietary software running in userspace, but of course it still has proprietary firmware blobs and proprietary UEFI firmware. I also have an old Thinkpad X220 running coreboot and with ME disabled (HAP bit set, ME technically still runs, but halts after hardware initialization) and unnecessary ME components stripped using me_cleaner. And my home server also runs coreboot with ME "disabled" and stripped but it has a BMC with proprietary supermicro firmware and an LSI HBA that also requires firmware.
Most software, but definitely not all. Steam, Resolve being the two biggest non-foss items on my desktop, while my ex-Chromebook has a proprietary screenwriting program, as well as OnlyOffice instead of LibreOffice because I need much better Excel compatibility for work and LO still isn't quite there for it.
Phone android. But not entirely de-googled. Replaced drive with syncthing, keep with Joplin, photos, phone, and messenger with their Fossify equivalents and disabled the originals. Replaced gboard with heliboard, etc...
But can't/won't completely replace the OS yet because both google pay and android auto are essential to me and getting them working on most replacements is still a royal pain in the butt.
Daily computing is mostly FOSS programs and my laptop is sold with Linux preinstalled (though I bought the higher spec Windows version and installed Linux myself. Cloud is FOSS, self-hosted in the public cloud (until I get fiber). Phone is rooted Android w/ FOSS apps wherever they meet my needs. I'm about 50% through degoogling and de-Microsofting. Ereader is KOReader (FOSS) running on old Kindle brand hardware. Keyboard is Ergodox Ez which I think the firmware is FOSS. Smarthome is still Smartthings which is not FOSS.
Did a fresh install of linux mint recently, because of that a good chunk of my software has been FOSS, however, when it comes to all the gaming related stuff I've installed (drivers, clients, etc.) its been a hit or miss with more proprietary software then i'd like.
Will say, I've struggled for a while to find a good open source music player for local files, I'd love some recommendations (currently trying Rhythmbox but I don't feel I'll love it)
Arch on every box in the house, including the primary router. Mixed Intel and AMD. Openwrt on every AP (unfortunately Mellanox and MediaTek firmware blobs for the radios). GrapheneOS on my daily and LineageOS on my legacy phone.
Aside from occasional games, I don't install anything I don't have the source to. My phone is the only exception, for apps required to interface with the rest of the world.
Increasingly so over time. Will try to install coreboot on my laptop soon. I avoid proprietary blobs where possible too but for stuff like the kernel, proprietary blobs are kinda unavoidable if you want a fully functional system. Tbf I've not tried linux-libre but I just assume it won't agree with some of my tower PC's hardware.
Aside from low-level stuff, I do still use Steam (and the proprietary games on there) and Discord—Steam cause all my games are there and it's convenient, and Discord cause a few of my friend groups primarily talk over Discord. Been considering setting up a Matrix bridge for Discord but I don't think that meaningfully achieves anything since it'll still all be on Discord's servers which are proprietary. I also occasionally install proprietary software to read proprietary file formats and would usually uninstall once I'm done reading the file.
FOSS for everything on my laptop and server, except discord and Spotify, but I’m migrating away as much as possible. I have a Pixel 7 with GrapheneOS and use mostly FOSS there too, but have Google play installed to the sandbox for some social media apps. Not perfect but pretty good and improving