Haven’t had a chance to really look into it, but there’s also spacebar chat which is an open source selfhosted reimplementation of the discord backend that can be used with existing discord clients and bots and stuff. Which depending on how solid the rest of if is, could really help existing discord people move with less effort.

One big downside to ham radio (as someone with my license) is that you can’t use encryption. Which is fine for some use cases, but does limit the usefulness in the “government shut down the internet” kind of scenario.

Which, I suppose if you’re already using back-channels to circumvent some broader government censorship, maybe abiding by FCC rules isn’t a priority anymore, but IMO this is an area where large mesh networks of “consumer” devices with encryption very much still has value.