alt Hacker News> If you find 4-5 apps doing basically the same thing (like communication or productivity tool), see if you can consolidate them into one.
If I could get all of my friends to switch to one communication app, that would be great, but that's only going to happen if they can get their friends to switch, and so on. Unfortunately, doing so requires them to install additional apps for communication, and no one can get everyone they talk to to switch, so they're just going to have more people on one app than another and in the end the problem gets worse.
Matrix bridges solve a lot of this problem, though... aren't really reducing complexity at all ends of the system. It does radically reduce end user app complexity, though.
I've been hosting a Matrix homeserver for... oh, 4-5 years, now, and I have bridges installed for my use and a few other people who use it that bridge Signal, Google Chat, Facebook Messenger, and maybe one or two other services into Matrix - so I almost never have to bother with the other clients, I just use a Matrix client everywhere. There are the occasional quirks you have to deal with, most of which are solved by upgrading your bridge (and the new bridges are a lot easier to deal with than the older ones).
As people decide to go Matrix-native, I can talk to them that way as well.
That said, as far as non-Matrix options go, Signal seems to be a fairly common one and easy enough to get people to switch to.