With the war with #Signal that's slowly beginning to rear its head, you probably shouldn't devote yourself to it. Signal is great, but it is centralized, it's a single company, and if that company goes down, that's it — and then you have to build your contact network all over again. With how hard it is to move from platform to platform, I still strongly recommend using #Matrix instead, specifically because it's decentralized. Every government in the world could declare it a national threat, and it still will never go away, just like fedi or the dark web, or the internet itself.

Furthermore, the Matrix.org Foundation itself knows nothing at all about you, and your server only knows what you put into it when you sign up (which some servers, like mine, require nothing at all). Signal, meanwhile, knows your phone number (which is itself owned by phone companies and therefore not actually remotely secure, and it's only a matter of time before they're required to turn on users).

Matrix also has bridges to other platforms that you can use to interact with those in your network who aren't ready to switch away from other services, and hopefully to help bring them in.