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.

Uh.. not my phone I'm only making the OS for myself anyways if people don't like the idea , and I might have mislead everyone here but I want a user friendly way to edit and create custom UI in the smartphones while not being as complicated as linux