From experience WebRTC starts to fall down in rooms of more than 8 people for video chat.

Meanwhile Zoom and Discord (who use servers) can achieve much greater so YMMV

That said p2p definitely has its advantages

Its just a case of p2p with people running servers (like bitcoint does) and differentiating between the two based on a bandwidth test.

Doesn't WebRTC need a TURN server to proxy traffic when you're behind a NAT? It's not really peer to peer when all the data goes through a central point.

TURN only proxies if it’s unable to make a connection via STUN, which requires the server to handle only a few packets when the initial connection is formed and provides direct peer to peer access after. Many home NATs only need the latter.