That effectively requires a cartel with high barriers to entry, otherwise not doing that is an immediate competitive advantage to any new challengers. It's pretty hard to build your own last mile telecommunications network, how hard is it to build a ride sharing app?
Price is not the only factor for me as a consumer. The other is availability, or time to wait for pick-up. That is determined by how many drivers are around.
Similarly, drivers like to have their next ride soon after their current one ends.
Thus, you have economies of scale for multiple reasons (big upfront investments for app and marketing, network effects).
That's assuming the incumbents are giving the premium for those customers to the drivers.
But even if they were, the drivers are in a competitive labor market. If you get the customers with lower prices then you can also get the drivers because they'd rather be working for your rate than not at all.
But you will never get customers without drivers and you will never get drivers without customers.
Plenty of Uber/Lyft competitors have tried and failed. Heck, a few different companies tried here in Austin once we grew a spine and banned Uber/Lyft, only to die as soon as they came back to town.
