(Edit: I'm Croatian and fairly well aware of how taxis work in Europe)
edit: And Uber charged me a fee to cancel the no-show ride and I had to call and argue with them to take the charge off.
Uber Pop got kicked out in a couple of months with Uber having to pay the social security costs of the employees. Now it's just an aggregator of Taxi companies, same with Bolt. The possible margin is minuscule since the drivers change apps depending on which pays the best. Often having both open.
For the companies themselves it's an extremely cutthroat business. From what I have heard the only chance to make any money is to own about 50 cars and have all maintenance in house. Otherwise it's just a fools attempt at being independent.