Linux ppa not maintained and very old

[Abbanon]

To sum it up:
The majority of PPSSPP's userbase is found on Android and Windows.
So the lead devs try to handle those builds as a priority.
Meaning there's no reason for them to waste time updating the other builds on top of those two, since the userbase for those other builds are very small by comparison.

PPSSPP is open-source though, so if anyone wants to step up to the plate and update the Linux version themselves, they are more than allowed to do it.
We're just waiting on people to step up and do it, basically. If they want it, they can make it. And then we can release it as a download.