EVs will dominate the market at some point in the next 15-25 years or so.

Tesla is priced as if it's going to absolutely dominate the automotive market. And there's no reason to believe that's true.

Automotive is currently a super fragmented market with many players, why will that change in a couple decades when it has been true for the past century or so?

There will be at least 3-4 major players in NA just as there are now, maybe more.