I use Firefox everywhere which means I have ads blocking everywhere, including and especially on Android. All my tabs are synced and are easily transferred between devices.
While I dont use Firefox itself any more I am using librewolf on my PC, which sadly doesnt exist for phones yet. Also, GOS comes with its own privacy oriented chromium fork called vanadium, so I'm using that in the mean time.
I also use librewolf and have settled for iceraven on my phone. the list of installable extensions is much longer (even if not everything is working yet, depending on how far mozilla has come along) and it has about:config support, which gives me a pretty close approximation of my desktop browser.
I've found the Mull browser (which can be found through the DivestOS repository on F-Droid) works great as a privacy-focused firefox fork, similar to LibreWolf. I hear Fennic F-Droid is also a pretty good but less extreme alternative, but I'd imagine you don't care much about that if you use LibreWolf.
I use it on a Pixel 5 and even there it is fluid while browsing. Only on Youtube there is the slightest stutter for HD Videos. Heavy sites like Discourse fora or Cryptpad or such work flawlessly.
I use both on a Galaxy Fold 5 and can confirm Chromium based browsers are smoother. Although I still use Waterfox on my phone. I just keep a Chromium based browsers in case a website doesn't work when I visited it using Waterfox.
There are other ways to block ads. Adguard does a great job on Android. It establishes a local VPN, so it can do HTTP[S] content filtering in addition to DNS blocking.
Can't use my VPN and adguard at the same time iirc, unless android has two active VPN "slots" now. Can't bring a pihole with me 24/7 either as much as I would like to.
Yes because there is no need to setup another VPN. You only configure the DNS settings (Private DNS). I know that Mullvad on PC has an option to use custom DNS server
Ive been using Firefox on Android for years but it really needs some TLC. It doesn't support scaling to a tablet/desktop UI at all so it doesn't work well in DeX or anything larger than a phone. I also recently had to swap to Brave because I noticed Firefox was draining a lot of battery all of a sudden. There's some kind of leak or running process that isn't sleeping properly. In a few months I'll re-install and try again.