I store every photo and video I’ve ever taken [hundreds of GBs, first photos are from my teens in high school circa 1997] in Apple Photos; highly recommend it. Yes, you pay a bit for the storage. Yes, it’s a closed ecosystem. Yes, I also backup my originals to Backblaze. But deprecation, ever, is highly unlikely while the UX is top notch. More good things coming for photos in iOS 13!
Because Drive integration for Photos allowed me to do exactly that. Last I checked iCloud will lock down all my photos onto a platform that's not even accessible on Linux.
I have iCloud Photos and pay for it, but I want to make sure I have a local backup too so I use NextCloud to sync to my NAS (which is running a NextCloud instance). You could also use the Plex app, or there's things like Resilio Sync that can auto-upload photos.
I'm not aware of an open source solution for auto-upload other than NextCloud (and possibly OwnCloud, but I don't use it), but I wouldn't be surprised if there was one somewhere or an app that did auto-backup to SMB/CIFS/WevDAV/whatever
“Lock down” is hyperbole. You can mount Apple filesystems (including the one storing your photo library) from a Linux workstation or server over the network.
I admit that if you’re looking for an open API for photo management, iCloud is not for you. But it works for most people.
I share my Apple Photo albums with android users without issue. I hope this was helpful despite your snark. I’m just trying to help.
Most people’s time is worth paying for something that just works.
Occasionally a drive will fail and need to be replaced, or a photo will disappear or be corrupted by gnomes, but I don't mind tinkering with it.
My wife, on the other hand, is an iCloud devotee, and has almost 200GB of photos backed up to iCloud. Pretty much every photo she's taken on every one of her iDevices since the iPhone launched. It has never lost a photo. It automatically tags everything. It automatically syncs to her computer and iPad. She can access it from anywhere.
If there was a sane way for me to import and manage 30TB of raw photos in iPhoto, I might follow her lead.