For people that never want to car salespeople again, buying a Tesla is a dream. I bought mine online and talked to someone for a total of 5 minutes. It was the best car buying experience I have ever had and can't imagine doing it any other way.
Buying a Tesla online is a dream if you are buying it cash (or don't really care how much a month the car will cost) and have no trade-in (or don't care what you get for your car).
If you are financing you can't lock in any rates when ordering because banks only lock for 30 days or less, so you're risking $2,500 in case you can't find a loan at a rate you're willing to pay when the car shows up. Also, the online experience doesn't give you any options to customize. Again, if you don't care a about hundred or thee hundred extra per month, then sure, just click agree and wait for them to tell you how much.
Trade-ins are worse. They will lowball you just so you try to sell it yourself as they don't want the car. I once even found a dealer who was willing to buy a car at a higher price than Tesla offered me, but even though initially they said they would do the "trade-through", they ended up saying no to it. The price difference was about $3K, which was a wash since I would get $3K worth of sales tax credit from Tesla if I traded the car to them instead of the dealer. Even when trading an older Tesla, trade-ins are still a nightmare, when I did that, they gave me a trade-in quote valid for 7 or 9 days. By the time the new car showed up 6 weeks later, my old Tesla was valued at $9K less - that's $1,500 per week depreciation. I sold it privately to recoup some of the loss (there was an EV tax exemption in place then, so didn't lose any sales tax credit).
So, while I've met some excellent people at Tesla, the processes imposed by corporate make the process not so pleasant unless you're just buying one with cash and no trade-in, then it's awesome (my first experience was like that). As a comparison, I've made deals with dealerships as far out as 9 months where they guaranteed me my trade-in value (with some limitations on how many miles I can put on a car). And it wasn't some fancy exotic car either, I had an Acura Integra and ordered a Toyota 4Runner which was not yet in production. Porsche dealer gave me a similar deal with 6 months out custom car order. While I've hated the fact that I had to spend hours to make a good deal with dealerships, with Tesla the same hours or more are just spread out in chasing appraisals, financing, etc. Again, if you have no trade-in and cash in hand, the process is a dream. There is something to be said about going to a dealer and driving away few hours later in the new car, having left your trade-in and knowing down to a penny what you're paying.
I was a big fan of Tesla non-dealer model, especially that my first one had no trade in and I had cash. 3 more after than made me miss some of the aspects of the dealer process. The fact that my wife's 6 month old Model S trunk won't close sometimes leaving the car not drivable safely, and the first appointment at a service center is a month away, that also leaves me missing the dealers, and serious manufacturers who can produce a car I can buy and not have to keep fixing. The fixing was an annoyance when service centers were not overloaded so you could get in quick, but with recent doubling of the fleet with Model 3's and not doubling of the service center resources, that is now becoming more than just annoying.
