I believe I've tried that back to the age of android 6 and successfully turned one of my old phone to a mini server. However I'm not sure whether the current versions it would be easy to even bootload and config the moving parts yourself. What is your primary use case?

>working with Android from the past few weeks

>Why has noone done this before?

This is a joke.

Why not use GNU/Linux if you want "Linux level customization"? Mobian, postmarketOS, PureOS already exist and work on phones.