I tried all 3 for the 2020 and they all gave me quotes. Carmax was the highest. The quotes I got from high to low were Carmax, Carvana, Vroom, Dealer.
Based on what they paid for my car, I don't think I would ever buy anything from them!
Maybe the 2021 is so new they want you to go in, not sure. I really expected them to find every tiny defect and start lowering the quote once I was there. It took about 1.5hrs total but the inspection guy only took about 10min and didn't even get in the car or drive it! Just let it idle while he took pics and walked around, opened/closed everything.