[edit] as I'm rethinking it, would this just be for searching your own images for a particular person...?
My Synology NAS has face recognition and it is wonderful even if (actually: especially since) it has no pre-existing database and doesn't (to the best of my knowledge) share its database.
For someone like me who manages family photos for the entire family but isn't to good at recognizing faces it is just brilliant.
I wonder if it's a good idea to use Synology as onsite, and ente as 123 backup solution?
Google photos has come in so clutch when you're searching through 50k photos.
You will be waiting a long long time for that.
The only way they can do that is client side, and if they go there we are back to the last few weeks discussion of Apple's new client side image scanning shit.
You do not want this service, it seems.
You want a non Google service who can do face recognition, and object/scene detection, but who'll pinky promise you they won't sell you out to advertisers or law enforcement or governments, even though they obviously could.
Apple has always been indexing images on the client side. What changed is that they're now reporting the presence of a predetermined set of hashes to authorities.
If governments were to mandate that such reporting is necessary, it is likely that the enforcement will be on a device/OS level, extending the example set by Apple. Demanding compliance from every single cloud storage provider out there (E2EE or not) would be a sub optimal route for them to take.
My point being, "client side indexing" is not the evil here, and it is unlikely that storage providers will be the ones forced to share data. Your concerns should probably be directed at your operating system.
What iCloud Photos is doing for their client-side scanning is: (1) Not to your benefit. There is no positive outcome for you from your photos being scanned. (2) Mandatory if you want to use iCloud Photos.
In contrast, I presume this would be- (1) Only to your benefit, because all of this derived metadata around scenes and faces would also be encrypted end-to-end as part of the photo library. (2) Entirely optional.
Increasingly powerful GPU compute being released and constantly improving image recognition models out in the wild. I'd bet there's a nicely packaged, open source solution released in under 3 years.
Either you're whining about their entire ecosystem of encryption, key sharing, mobile apps, desktop app, web app, etc - not being worth a cup of coffee a month "Cause I can do it all myself using S3!!!", or you're planning on storing many times more than ~200GB on their platform.