I don't believe that Uber/Lyft/Someone can't operate a ride sharing service at a profit. Taxis have done it for decades and now that the technologies have been invented, I don't see any reason Uber/Lyft can't ever be profitable. They may not be profitable enough to justify the amount of investment they've received, but they'll likely still exist in some for or another.

The cat is out of the bag. Nobody is going back to taxis.