Privacy

I've definitely also thought about, if our government gets taken over by fascists, how do you organize a rebellion?

And yeah, Signal definitely has some weird fucking shit going on. As far as I'm aware, they don't allow you to use their centralized servers, if you don't use their provided build of the app. They don't seem to have a mechanism to enforce that, so you could still use a self-compiled build, but if all your friends are on a compromised client, you can't talk to anyone anyways.

Well, and then there's also the great stupidity that Signal requires a phone number. In my country, you can't sign up to a mobile phone plan without revealing your full identity. If the fascist government realizes that I'm part of the rebellion, they can make my phone number disappear in unfortunate circumstances.

So, yeah, I'd at least want to self-host the communication platform. I'd probably use an existing open-source solution, but would try to audit at least part of it...