Been using their bridges for over 2 years, super happy that I no longer need WhatsApp installed on my phone.
If you're like me and live in a country where a shitty chat application is required to be able to function in society, software like this is a breath of fresh air. The bridges are also super stable and incredibly well written.
Note: to be clear, I don't use beeper itself, but use their open source bridges (what beeper is using internally) on my own self hosted Matrix server.
The one thing that sucks about bridging and is never likely to be solved is voice calls through bridges. Theres really no good way to implement it as you would essentially need to have the bridge call you through matrix after you get a WhatsApp call.
As a person who's been using said bridges as his primary form of contact for years, it's very difficult to tell people: "Hey, I'm not actually reachable on Whatsapp/Signal/Telegram, please just call me instead".
As a result, I have a backup "net phone" in one of my cupboards with each of those apps installed. If I'm dealing with a particularly stubborn person I have to use it as a fall back.
So, while I love these bridges, your comment is completely valid and anyone thinking of using them should be aware of that.
TLDR, my Matrix chats are filled with:
> Person A (WA): Incoming call
> Me: I don't have whatsapp, needs to be a normal call :(
Yeah this is especially difficult if you're dealing with people overseas who have generally bad cellular voice service. I've had to relaunch whatsapp in another profile on my phone just to answer their calls.