As far as stock prices are concerned it may not matter much how many EV cars are built by incumbents if they are built at little or no profit. Simply replacing profitable gas cars with unprofitable electric ones.
Musk has said that the factory is the key. Building more cars faster at higher profits.
Wright’s Law https://canadiancor.com/wrights-law-is-the-best-way-to-predi…
Even at the same production levels Tesla’s factories are more productive. Partly because incumbents have “model years” and introduce improvements less often ,and not while the line is in motion. And must constantly be aware of the effects of change on auto unions.