Not really.

It's trivial to change retailer, not so changing which app-store you use, especially not on Apple hardware.

No it's not trivial to change retailer for some products.

I can't buy a Tesla, Tiffanys etc at any other place except their retail store.

If you add new tires to your Tesla when you sell them you can sell the new tires with it. Try selling your apps when you sell your old iPhone. Your car is also repairable. Your iPhone is meant to be thrown away. (Not an issue exclusive iPhones)

It is nonsense to say that iPhone is not repairable.

You can goto any city on this planet and find hundreds of small third party stores who will repair it. Everything from cracked screen, new case, battery replacement etc.