the issue i remember keep coming up is that there still isn't an actually good matrix client that approximates discord's layout. the basic logic of a community being on a "server" with multiple channels people freely swap between , with maybe some voice channels that are compeltely disconnected from the text channels, still isn't actually implemented because matrix still operates on IRC logic where every single channel is supposed to be a community unto itself. element's spaces feature is a very poor substitute, and withotu that basic killer feature i don't see any mass migration happening anytime soon.