Couldn't all of these chat apps change their TOS and forbid Matrix bridges like Discord forbid running through 3rd party client? You depend on all of those chat providers to allow you to hook everything in one app.
I assume they are offering a "puppeting bridge" which means it acts as you, however this means that it is using unsupported APIs and Discord has been known to ban accounts for this.
I think it is pretty disingenuous to put the Discord logo on the homepage without pointing out those caveats.