I have a pet theory that a four- or even three-star review would be fine in a rational universe. Ride in an Uber, and the driver gets you there safely, on time and the driver is reasonably personable? Three stars.
Four stars if the driver gets you there on time despite traffic, helps you with a massive amount of luggage, or you have a fascinating conversation.
Save the five-star reviews if you have a cardiac event and the driver restarts your heart.
But because I am not a sociopath, I do like everybody else and routinely give five-star reviews for acceptable service. I rarely give as low as four stars because I know that’s a big deal for the gig worker who provided the service.