They have scaled their manufacturing quite well be now. They are not top of the line but the have a real mass production car.
Have you actually looked at the production numbers of those other EVs? Because there is nobody outside of Tesla that has mass produced EV and even more imprtantly, to do it with profit mergin per car.
Teslas are the Top 3 most sold EVs in the US market. The model 3 is by now equaling the sum of all other EVs and is almost 100% of the growth in EVs.
Futhermore, the iPace, i3, Tycan and many others saw production delays as well. So the idea that you can let some established company do it and they will do way better then Tesla has jet to be shown.to be true.
The original Tesla Killer, the Bolt, is outsold by Tesla 15 to 1.
Competitors have announced many EVs but most will hit the market around 2020 and most of them will not produce near as many as the Model 3.