This is my retelling of what I surmized my mechanics friends telling of it, so what I'm saying isnt probably worth two shits, but he said independent shops are sort of getting locked out. You have to do subscriptions to use their software, their diagnostic tools, and you have to pay a fee to reprogram the computers when you add new parts, and many of those parts will keep giving error codes or not properly function unless its a OEM part.
He said once cars start getting more advanced with "saftey" features they get harder to work on dramatically. When all the updates start needing to come from 4g Sim cards in the car and can only work with their servers. Everything that's new new just has to start going straight to the dealer.