Pixelfed for Instagram to a certain extent. You can also use Instander for an alternative viewer for regular Instagram.

Revolt Chat looks like another alternative for Discord, but haven’t used it myself

just got to act 3, hearing about patch 2 makes me wanna put it on hold until it gets released just judging by what people have been saying.

Typical of Google to shut down yet another service

Is Quake II worth picking up? I have the first one but never played the others

+1 for NewPipe. Though if you view youtube on a browser with an adblocker (e.g. Brave, Firefox with uBlock Origin) you can still skip all the ads