The use of https://kosmi.io/ here is what I found more interesting. I've never heard of this service before but it's a great idea. Reminds me of some much less...polished chat services I've used in the past to group-watch videos. It's nice to see the concept fleshed out more with a public lobby and a Discord-like client.
Here's a link to the open source version of Quake called Open Arena, compiled to WASM and using WebRTC for matchmaking.