Other manufacturers have been making EVs for a long time. Tesla only had a free run at the US market but every traditional US manufacturer being asleep at the wheel doesn't mean Tesla were going to get that market for free.

It was all predicated on Tesla being able to dictate standards that were enforced by legal mandates in the US. It would give them a huge advantage over European and Japanese competition. That has never materialised and they've been overvalued ever since.