Taxis are monopolies in their area, yes.
Vehicles for hire use public roads and infrastructure. This they are regulated or the public roads and infrastructure get exploited.
Perhaps you are a pure Libertarian and believe only in toll roads and unlimited vehicles for hire. If so I can’t help you. We currently do not have that system and there is NO level playing field.
I’ll cite two examples. Taxis are limited in my town to 2000. TNCs have no limitation at all. By their own admission Uber has over 40,000 drivers here.
Every time a taxi company replaces a vehicle they have to do a months long Environmental impact Report and the vehicle must be hybrid. TNCs have no such requirement and can use whatever vehicle they choose
I could list a hundred other irregularities on the playing field. It is grossly unjust and I can’t Believe it’s been allowed for so long.
“Taxis are limited in my town to 2000.”
What other private businesses would you have the state limit in number by law? Package delivery services? (They use the roads also). Mobile car wash vans? Ditto. Wrecker/tow truck services? Private trash haulers? It has been my longstanding observation that in every case where the government hands out licenses to restrict competition, price to the consumer goes up and quality of service goes down. And the process of acquiring and retaining a license becomes corrupt, with politicians and bureaucrats lining their pockets with bribes from incumbent and new-entrant firms.