What does HackerNews think of immich?
Self-hosted photo and video backup solution directly from your mobile phone.
Conversely, Synology Photos (which I use instead now) has a fantastic mobile app. However, if you really want reliable and granular object/face recognition, the Syno app is a little bare bones. It does some face recog but that's really it. However, its backup feature is reliable and I don't have to worry about if it's working in the background or not. I tried Nextcloud's photo plugin for a while too, but its mobile app had issues and I just couldn't rely on it.
Another project I've been keeping my eye on is immich: https://github.com/immich-app/immich
I'm happy for now with Syno Photos but it would be nice to have my photo app in my container environment with everything else I run and just use the NAS for media storage like I intended to.
It's got a way to go to be a full replacement but it's already got a lot of the features and can handle huge amounts of images and videos.
It's fully open source and not for profit, if you also don't like our Google overlords having all your data, give it a try!