And Whatsapp requires whatsapp web so you need to keep the client running on your phone 24/7 or run it in an Android VM which is pretty heavy.
And finally the whole Matrix experience is a bit lacking IMO. It doesn't really do 1:1 chats so every time someone chats with you you get a 'room invite' from the bridge, which you have to accept, and all those old rooms stay forever cluttering up the system.
I wouldn't mind outsourcing all that work, but $10/month is a lot.. Good idea though! There's definitely a need for this, which is why I've been looking into it too. I'm just getting so sick of all these different chat apps screaming for attention all day, each with their own difficulties. Some don't work on the desktop, others only work on 1 client at a time. And each milking as much data as they can. Why can't people just stick to IRC :)
The issue is that most of the services Matrix tries to bridge to are basically hostile entities (except IRC and Slack). I'm honestly shocked how well Matrix bridging works when you take that into consideration -- and unsurprisingly the Slack and IRC bridges are the nicest ones to use. But I will admit that I think Matrix's marketing around bridging as being core to their chat model is a bit of a stretch -- while all of the bridges do work, most are a bit dodgy (and some require you to self-host).
For instance, the Signal bridge is actually a hacked-up version of the Signal Chrome App with a bunch of hooks added so that they can simulate you doing things through the web app. There is a project that uses libsignal-service-java directly to create a more usable CLI and DBus interface[1], but unfortunately they haven't switched to using that (and if it became widely used, Moxie would probably decide to block it). Whatsapp is probably similarly hacked-together.
> It doesn't really do 1:1 chats so every time someone chats with you you get a 'room invite' from the bridge, which you have to accept, and all those old rooms stay forever cluttering up the system.
Maybe this is bridge-specific, but I have several long-lived IRC 1:1 chats that are all in one room. There's nothing stopping a bridge from doing this correctly (as far as I know). As for old rooms cluttering up the system, I believe that (non-joinable) rooms with no members get garbage collected but I might be mistaken.