Well, in truth they most likely have something like a decade or so to adjust which is both not a lot and enough for such organizations to adjust.
Sure some manufacturers will go bust and collapse, but other will adapt, and new ones will be created.
I'm quite puzzled by Tesla's valuation, such a valuation is betting on it becoming a huge actor in the post IC automobile industry which is not a given.
I'm also skeptical about the "Iphone moment", functionally the Iphone was a huge step forward (basically having a small computer in your pocket vs having something just doing phone calls, SMSes and snake), but a Tesla, well, right now, it's still a car which does more or less the same thing as any other car (just slightly better in some aspect, slightly worst in others).
It's also not the same market, the Iphone appeared in the booming market of mobile phones which was seeing exponential growth at the time. And also, the gain in functionality and convenience was enough to transform the market from consumers willing to pay at most ~100$ for a flip phone to consumers willing to pay 1000$ for a smartphone with all that entails in term margins and profitability.
The car market by contrast, is not seeing such a growth, and it's unlikely consumers will be willing to spend that much more for their car.
There are potential market shift possible which could be caused by things like reliable autonomous vehicles, tighter regulations forbidding IC vehicles in some cities, cheaper cars (as EV are mechanically simpler, it's a possibility), but these are somewhat elusive.
Tesla valuation is at the very least a huge bet.