Never, not once in 15 years, have I had a cab claim their meters are down. I've suspected a padded fare a couple of times but the difference was so small, that as a native I didn't notice. Credit card readers being down used to be a common refrain, but seems to have gone away in the face of Square.
What I have had, not commonly but often enough that it no longer surprises me, is extremely racists statements about where I live (I'm a white south sider which seems to attract crazy talk). This has occurred in taxis, Uber & Lyft. I've even had Uber and taxi drivers (Lyft isn't immune, just small sample size) try to refuse to drive me home after picking me up. I've reported these incidents to either 311 or the respective apps. With the apps I have no idea of the effectiveness. With 311 I had a case number assigned and received an update months later when a driver lost their license over a racist incident.
If I really had any complaint about Uber & Lyft is that it seems to have driven the profit out of livery cars and really created a race to the bottom in that market. I used to much prefer private cars for most things, but now the difference isn't worth paying for except for prescheduled events.
All that said, I use taxis, Uber, Lyft & livery cars with some regularity, and my usage of them largely is based on convenience not quality of service. Taxis when I'm in the loop or some other busy spot, Uber/Lyft when I need an adhoc ride elsewhere, and private cars for scheduled rides.