There is an audience for this, and it's me and my friends.

I have a small group of close friends. We are on discord just about every day, but we really don't bother with anyone outside our group, other than the very occasional invitation to another friend/coworker to join for some games.

We don't care about network effect, social media features, engagement, etc. We just want a well made application for private text, voice, and video that we never have to actually think about.

And no, matrix is not that.