Linux ppa not maintained and very old

[[Unknown]]

That'd be very strange if true. The Windows and Android community has seemed happy with the updates in the past few years, improving speed and compatibility in a lot of games. Most of these improvements apply to Linux as well, but anyone is free to contribute their own improvements - it's open source after all. If you're personally not satisfied, the best way to fix that is to roll up your sleeves.

Discord can be easily disabled at compile time. The current code we use is actually MIT, I think, but it's deprecated and the new SDK they want us to use is apparently indeed not GPL compatible. It sounds like your comments might be about another emulator that is using this other SDK? Definitely a concern if it impacts emulator performance (the current one we use has negligible performance impact afaik.)

PPSSPP is a community open source project. Someone came along and contributed a PPA. They've moved on with their life after several years. No one else has stepped up to manage the PPA and I'm not sure anyone still involved has access to it anyway. Anyone here volunteering to help with that situation?

-[Unknown]