Have you considered buying yourself a portable hard drive and backing up anything/everything you want to make sure is safe onto it ? The cost is around £45 or less for a 1Tb drive and it takes you next to no time to do the copying over - it is yours and yours alone, as accessible as you care to make it. But in the case of data on a phone you would need to cross the phone/computer interface.
Did you check Google photo. If you log in to Gmail or other google app and turn the sync on then it will automatically save all your photos. Check Google photos.