Won't this make my telephone service provider + phone a single point of failure? Good thing it's not SUPER EASY to steal someone elses phone number, and also a

Won't this make my telephone service provider + phone a single point of failure? Good thing it's not SUPER EASY to steal someone elses phone number, and also a good thing that modern smartphones basically NEVER break. I think I'll just stick with my FinalKey which I can build extras of and which can store the encrypted database and backups offline.