> I cannot choose any of the parts, and even doing simple reparation tasks like replacing a battery is a nightmare these days.
There is the https://www.fairphone.com/en/ which is a modular and easy to repair smartphone. They also make it easy to install alternative operating systems like Sailfish or an OSS version of Android.
The company itself only supports stock Android, although they do foster (some) community efforts for ports. Sailfish doesn't seem available for the Fairphone 3; /e/OS is, but to get it preinstalled you need to order from E, not Fairphone itself: https://esolutions.shop/shop/e-os-fairphone-3-plus/
Unfortunately they don't seem to work in the US, and from what I've seen they are mainly focusing on selling and making sure their phones work in Europe.
