Not the best answer because it’s not open source, but both Google Photos and Apple iCloud support automatic cloud backups of photos and videos over data. That media can also be accessed separately from a browser or another device after logging in.
Those are the only immediate solutions for the problem you describe that I can think of off the top of my head, I’m afraid, but hopefully other options are out there, too.
Not the best answer because it’s not open source, but both Google Photos and Apple iCloud support automatic cloud backups of photos and videos over data. That media can also be accessed separately from a browser or another device after logging in.
Those are the only immediate solutions for the problem you describe that I can think of off the top of my head, I’m afraid, but hopefully other options are out there, too.