For all its flaws and spaghetti code vulnerabilities in WP core have been really really rare. It’s usually some plugin that’s vulnerable. And automatic updates take care of timely patches.

Despite MPV being simpler VLC usually has less problems to play something than MPV. I don’t really like VLC’s interface, but I DO like how powerful it is without having to read any manuals.

At least voice and video are often done peer to peer. So the strain on the server would be almost zero.

Skill issue

Fitting that r/selfhosted can’t selfhost.