I'd be afraid of a bad review if I told a passenger I'm not happy driving for Uber.
What do I have to gain from sharing this info? At best I'm where I was before and at worst maybe an Uber employee is testing me for fidelity and I could be punished. The truth is somewhere in between, and a non zero number of passengers would rate me a non-5 star if I complained about my condition.
So take the info with a grain of salt.