One of the things I like about dealerships is competition. I have both a Subaru and Hyundai car, with about 7 or 8 dealers each within a 45 min drive of where I live. That gives me a lot of choice about where I buy and where I get it serviced. If they are not competitive they go out of business. As a result, I have had great service and pricing from my dealers over the years. They even compete with the after market shops, and will even source a used part for an older vehicle (starters, alternators, etc) if you want. I have had that, with great savings.
My son has a Tesla, and until recently only 1 service centre, now 2, where he could take it. He had to book weeks, and even months one time to get something fixed. And it was very expensive. Plus no negotiation with Tesla, they are in full control of all pricing, and their inventory availability. It's crazy what he had to pay for simple accessories, like a roof rack, and extra set of wheels (for winter tires). I don't like that, when I have to pay through the nose.