You can replace the OS on most Android devices.
Specifically- devices made by Google have been unlocked allowing replacement of the software.
You still have to put together a working kernel and drivers, environment, etc.
Not much stopping folks from doing that though.
GrapheneOS, Ubuntu, and others have made headway for some devices.
Each device potentially uses different hardware implementation and features.
You’re a breatharian? No corpse munching from you.
Are you pure enough that you feed the bacteria in your body without suffering?