Is your phone also made of indestructible materials so it can't break, and magnetically linked to your person so it can't be stolen? Backups exist so you don't lose precious photos/data if you lose the device. Most People™ do not have the technical knowledge to set up a self-owned backup system, and/or will not realize how badly their future selves will wish they had backups if the setup friction for a self-owned solution is too high to conveniently do it right this second.