Free and Open Source Software

Nextcloud, as mentioned, is a great option but does require a bit of work, albeit not much. I would recommend a Synology server. They're fantastically simple and this was my approach after trying Nextcloud. I did this to divorce myself from Google. Synology has many mirrored services

I've been using Immich. Very useful and easy for non techies to use. I know it says beta software, and it is; but it is more reliable than Lemmy...

it deletes it from my phone to clear space, keeping only the cloud backup

One copy of of anything isn't a backup, it's a move. Yes, in this case, Google is doing its own backups but you're giving them all the trust and control.

Immich! I've been using it for a while and it's amazing

I replaced Google Photos with a Synology NAS + Synology Moments (app). It handles the backup from my phone, organizes the images, has facial recognition, object recognition, etc. Object recognition was REMOVED from the newer Photos app, but Synology is apparently bringing that feature back this year.

You can clear up backed up photos from your phone through the Moments app (not sure about the other Photo apps from Synology), but you'll still want to have an actual backup solution for what's on your NAS.

If you can setup a small server (nothing fancy, an old refurbed office PC does just fine) you can setup NextCloud. I use it for a Google Drive/Photos replacement. Doesn't have as many nice features, but it works if al you want is archiving.

You can also check out the Self-Hosted Git Guide, there is a whole section for Photo/Video management. https://github.com/awesome-selfhosted/awesome-selfhosted#photo-and-video-galleries

Another vote for syncthing. It just magically works in the background and is very reliable. I take a photo on my phone and within seconds it's on my Photos library on my computer. (gThumb and/or Shotwell for Linux work well. )

Since we're discussing alternatives to Google, does anyone know of a self-hosted alternative to Google's location sharing? (For family members etc?)

I use Syncthing to get the photos and videos off our phones, and Photoprism as the photo library.

But I'm looking to see if there's a decent replacement for the latter, as the promised multi-user support that was eventually delivered was made a paid feature, without any acknowledgement for those of us that were paid up Github supporters up to that point.

I'm sorry for my rec since I'm not sure if it fits your needs or spec, but I use SyncThing which seems to support everything?

I'm also not sure since I don't use it, but you could theoretically get a tasker or automator setup to force SyncThing on Wi-Fi to your backup server and another/same one to delete them monthly/based on storage space?

It's not an all in one, as I don't believe SyncThing does transfers but makes copies? Unsure, this seems like it may be an option for you!

Bonus: if you have any kind of music collection that you like digitally, it makes it very easy to have an automated library :)

Apart from the ones mentioned there's also Murena cloud. Good if you have e/os phone

Immich - GitHub

Ente.io is also an option

This was one of my last de-googling projects, I currently self hosting photoprism, I have syncthing that syncs my photos to a network attached storage....at 3am it copies those pictures to a permanent location (I do 3am because during the day if you want to delete any photos etc. Before it syncs with photoprism.... At 4am my nas backs up to another nas (they are just a few portable HD for redundancy) photoprism works great for me, not as powerful as say Google photos, but close 2nd for me..... And for accessing the photos when not at home, have setup wireguard VPN for away from home access....... I see you want automatic deletion of the photos on your phone, I'd say you be able to run a CRON job that maybe every day (if you have made sure that your pictures are for sure being backed up in the middle of the night, that would automatically delete your dcim pictures folder..... I also run graphene, I'll give it a try and let you know if it works

P.s. my NAS drives are connected to a raspberry pi

crypt.ee is a great alternative, which is extremely well designed. Included in the subscribtion is an online document editor for personal notes and documents. Everything fully encrypted of course & works across all platforms.

I'm using Synology photos. Auto backup for everyone's phones. Shared common library we move things into for all our photos. I miss some of the ai search capability of Google, but never enough to do anything but self host.

Nextcloud is good. I actually have an instance on my server if you need one. A+ rating on server security test lol