As many others have pointed out, Tesla is a lot more than a car company and its success is based on a lot more than just building electric cars. In skimming the comments I see many the mention that Tesla is really a software company. To date, the tranditional car makers haven't gotten good at making software and doing live updates in the manner that Tesla does.

Tesla has one other huge advantage that isn't likely to go away in the next few years, the supercharger network. Most electric car charging happens at home, but if you want a car that can take you between cities, you have to have a network of rapid chargers that is fully integrated with the navigation software in the car. Tesla has that. Other car companies could, but so far I haven't seen them making in moves in that direction and even when they decide to start, they will be years behind unless they license tech from Tesla.

The last part goes back to the first bit. Tesla isn't just a car company. If all the other car makers wind up licensing a lot of tech from Tesla, Tesla still wins.