Generally you pay for some kind of permit to be a taxi driver. A quick google suggests in excess of 150KUSD:
https://www.bostonglobe.com/ideas/2015/08/05/what-about-taxi...
So they potentially have a lot to lose...
https://www.bostonglobe.com/ideas/2015/08/05/what-about-taxi...
So they potentially have a lot to lose...
Oh and all the regulation should be the same for taxi vs ridesharing like insurance requirements (commercial insurance is much higher which taxis are required to carry) and inspection requirements etc.