You can absolutely buy a Tesla and operate it for the life of the vehicle without an app or even a smartphone. They have key fobs and keycards for this purpose. Go into the store or order online. Everything can be handled by the Tesla store if you are selling the car and need to transfer it to another person.
Of course, having to go to the original store to sell a product second-hand ain't exactly the best user experience either.
(It's fine by me, if that's their design and I don't think they are hiding it or tricking anyone. People should be allowed to buy products that I don't like.)
