Of course her name is Karen

If you have a server that you can sync the photos with (using Syncthing for example), then I recommend using Rclone or Duplicati to save your backups (encrypted) to any cloud that you want. I'm using OneDrive and GoogleDrive for my encrypted backups, pretty happy with the setup.

If you don't have a server, then Filen or Proton Drive looks like great services.

Whatever you do, always test your backups!

Yes, both Rclone and Duplicati will handle the encryption for you. For Rclone, there's an Android app called RCX that lets you access the files. The reason I sometimes use Duplicati is because of the incremental backups, where I don't think it's possible for Rclone. Rclone is literally a clone from your disk to some cloud.