@Niall my replacement for Google photos is Immich - https://immich.app - I've been using it for a few years for automatic phone photos & video backup (can share media with family & friends, or even let them my immich for their own backups as well). It's superb. A couple of us are exploring offering it commercially among other services, right here in Aotearoa. And yeah, NextCloud is also an excellent option. Happy to chat about it (or give you a 'walk through') if you're interested.