I already had KiCad installed, so I uninstalled it to see how long it would take. It took me 51 seconds to clone the repo and reinstall KiCad. I thought this wasn't too bad.

But the joke was on me — when I tried to open the PCB file, KiCad said: "KiCad was unable to open this file because it was created with a more recent version than the one you are running. To open it you will need to upgrade KiCad to a version dated 12/29/2024 or later."

So I now think your position is reasonable. Also I think I need to upgrade Debian.