Besides, the phone software is highly optimised for the specific hardware. It is not a generic software like Windows
But there's also nothing to stop you simply building the latest kernel from source and using that - it's pretty easy and it will work fine.
Seriously, why can't Android just be installed? Are they building it like the old-timey kernel before modules and embedding drivers in a giant monolith or something ridiculous?
https://source.android.com/docs/core/architecture/hal
Yes, it does (CachyOS).
Besides, the phone software is highly optimised for the specific hardware. It is not a generic software like Windows