I guess most of your "wanted" list is easily achievable, except the first one: There is just no self-hostable product for photo management that comes close to A

I guess most of your "wanted" list is easily achievable, except the first one: There is just no self-hostable product for photo management that comes close to Apple/Google in terms of reliability, feature set and ease of use. Take all recommendations with a grain of salt. They're not even close to the capabilities of Google/Apple (unfortunately) – no matter what people are trying to tell you. This is my experience from trying out most of these systems at some point in time (Nextcloud, Photoprism, Synology Photos, and more).