The one thing that would prevent your suggestion is the state DMV rules. These apply to all 50 states. Amazon could drop a package to you but a car is another whole thing entirely. When you are dealing with lenders, collecting taxes and registration fees and processing new car titles I do not see any state allowing that to happen outside of the dealership rules. Staff can certainly deliver cars to customer homes but they must be working from a central location within the state (think an airline hub and spoke system). Then you have the economy of scale issues. It will always be cheaper to have multiple customers come to you rather than making individual deliveries of vehicles. Do they do it in certain cases? Of course, but it is not the preferred method for a lot of reasons, liability being one of them.
Dealership locations are very effective for other OEMs because they can perform the three main functions all in one location. The biggest obviously is immediate new car sales followed by service and used car sales. The vast majority of our public is geared towards "immediate gratification". While some are willing to wait for a specific ordered car or truck most are not. This has always been an advantage of having acres of cars and trucks for them to choose from. Tesla, like Ferrari and a few others, is an anomaly. Will it stay this way? Doubtful.
Where most dealerships are independently owned, they still do the same functions as Tesla locations. They provide showrooms to view products, perform service functions, and have offices to process the required documents to effect ownership transfers. Tesla took an unconventional approach in many locations by placing showrooms in pricey shopping centers such as the one here in Jacksonville, FL. and converting a former paint store into a service and delivery center about 5 miles away where they are severely limited on parking and car storage. When these locations were chosen they clearly were not thinking ahead about how to deliver 53 cars per day or contain costs. I honestly believe not enough attention was given to the process flow for the distribution pipeline from day one. So now lets talk solutions.