I've finally deleted Uber and it's primarily because of the tipping issue. I've had almost universal good service around the world with Uber drivers, but the tipping thing is getting aggressive, and subtle hints are rapidly become overt demands. Uber was great when it started but government corruption and meddling, combined with Uber's greed, and the corrupt taxi industry fighting it, is killing the service. Small improvements could go a long way:

Add tipping in the app; ban cash tips. Require drivers to rate passengers BEFORE they get those tips.

No cancellation fee for anyone if cancelled within 10 minutes. After ten minutes whomever cancels, pays, period. Uber knows when it's inconvenient for someone to pick someone up due to traffic. The data is there.

Require background checks on all drivers. Why is this even an issue? Uber should pay for it.

Increase the amount drivers get. Seriously it's ridiculous how little drivers make.