LineageOS. Or Murena, if you can't be bothered to install it yourself. And then use f-droid, or if it's not available there, Aurora store. As seen on computers, OS is too important to be left to companies - if you value your freedom of choice and privacy, that is.
I am very much fed up and ready to get on board with you but one thing that holds me back is photo quality. Nowadays camera sensors are only half the story and most of the iphone-like photo quality is achieved in software. Have we reached a point where non-OEM apps can deliver something comparable to the market expectations from big manufacturers? I am ok with narrow combinations e.g. if you use app X on Hardware Y y…
In that no one cares about it unless they're in it.