Comment by ubertaco

Because dealerships are the automakers' real customers, at least right now.

You don't buy a vehicle from Ford; your local Ford dealership buys a large number of vehicles from Ford, and then you buy one of those.

Yes, an argument could be made that eliminating the dealership keeps the same customer base while eliminating the middleman (see also: Carvana), but now you have a lot more cost and logistics (shipping individual cars to individuals' homes, for example, rather than shipping truckloads to a single well-known spot) and unless you're willing to do the Carvana/CarMax thing of offering a 7-day return window (which adds even more cost and logistics and risk), the average American customer won't feel as comfortable buying a vehicle sight-unseen from across the country as they would if they could sit in the thing while a salesperson pitches it to them.

That means you're taking on whole new category of cost and risk, while assuming that you won't lose any of your incoming revenue.

That's kinda a big assumption, and the major established/legacy/whatever-you-call-them automakers aren't known for having a high risk appetite.