Ask HN: Android OS with Linux level customisation

The most technical limitation would be fighting with upstream (AOSP), if you make radical changes like the ones you're proposing, assuming you can even get it all to work, it'll be very very hard to keep your changes in sync with upstream, as Google tends to break these things. Even big and famous groups like Paranoid Android, who used to make radical changes to the UI in the old days, gave up because they couldn't fight the fight against upstream. Almost every ROM group around the same time also changed their strategy to be as in line with AOSP as possible. This was like 10+ years ago. Android today is far, far more complex, and security is also a huge issue with all the AI-driven vulnerabilities out in the wild, making it imperative that you update your ROM every month - but with the kind of changes you're proposing, it's impossible for one person to maintain such a codebase.

The only way it'll be feasible would be to use AI, but you'll quickly burn thru your tokens, because the Android codebase is absolutely massive. And with the amount of money you'd be spending on it, you might as well just buy a Linux phone.

This is a minor nitpick, but I don't think postmarketOS is GNU/Linux.

I am not sure what the correct term would be to refer to the group of operating systems including those you mentioned but excluding Android, since all of them include Linux, but it does seem like there's something different about Android that puts it in a different category compared to other Linux-based operating systems.