The previous version of the Uber Driver App showed you your rating, but not how it was calculated.
So you had no idea of how many different star ratings you had and so no idea of how vulnerable you were.
The new Uber Driver App gives you this detail.
Tap your profile image in the upper right corner of the main screen. You'll see three buttons, labelled Earnings, Profile and Account.
The Profile button will have your picture above, along with your current rating. Tap it and it will show you your image and rating again, plus your total number of trips and how long you've been an Uber driver.
You can also click the Add Details button to add more personal details that your riders can access if they wish to do so.
Click the rating itself underneath your image to see the breakdown of individual ratings. Your current Uber Driver rating is calculated from your last 500 rated trips.