I’m sorry if this sounds like a stupid question but why won’t android just straight up run like Linux distros that almost run on any computer? Why does each model under each manufacturers require separate maintainors seperately? Aren’t they running like almost similar hardware like processors from Qualcomm, mediatek, Exynos, etc? Why hasn’t there been a single android os that is compatible with all the device?
Hardware incompatibility between phones. The PC world is much better standardized.
x86 and its descendant 64 bit architecture get hardware initialization and discovery through BIOS, whereas in the ARM world (which is what phones are built in) hardware needs to be described in device trees (DTS) where hardware adresses, chips and drivers are matched
that’s the simplified, short answer
Does that mean that it is basically impossible to replace the hardware in an ARM Computer because of the mismatches?
not impossible, but quite a bit harder than the plug-and-play experience you get with PCI on x86, yes
but this is quite out of my field of expertise already