Whether or not it's profitable for Uber or any business to hire you, is that business' decision. It's not yours to make. And there is no evidence that ridesharing companies cannot afford to pay drivers more. What if prices go up 20-30% and the level of service stays exactly the same? Then it was a silly concern with no basis in reality. I don't think evidence shows that Uber will immediately fire all drivers if they must be classified as employees.
Do you genuinely believe that this change will have no effect on the market? That the number of people driving will be the same? That everyone will just be able to continue to drive for Uber/Lyft, on the same schedule that they currently do, but make 20-30% more?
I know that the answer is "no" since you've already said "they can just go work a fast food fryer". But that's hard to reconcile with this last statement of yours.
I, for one, would much rather drive for Uber than run a fryer. To the point of willing to take a significant pay cut to avoid the fast food industry.