Disclaimer: I have no inside knowledge.

I _suspect_ it's two things:

Firstly, as you suggest, is a lack of economies of scale, startup expenses, high R&D costs, etc. Existing car companies can do a lot of the EV manufacturing with known techniques, existing machinery, etc.

But secondly, at least Telsa has an absurdly high profit margin compared with traditional high-volume models. They're taking the luxury route of a smaller sales volume, higher per-unit costs, and making a good profit off each vehicle.

In short .. because they can.