Wow that is hilarious. This kind of fragmentation pretty much guarantees failure. I'm pretty sure it's what killed Thrift. See their similar "don't use this" table:
* Conversations, Gajim, Dino, Kaidan, things on omemo.top with a passing grade.
Things which are still not default working everywhere would be voice/video call, but if you adjust your expectations to "IRC with file uploads, no need for a bouncer, and encryption" then it's fairly universal to support all that.