Pretty much all the proof anyone should need to see positive ratings have a monetary impact.
I’ve had a number of models sit with no reviews while downloads and prints accrue. When someone finally gives a review (generally 5 stars) there’s a small windfall from the point bonus for good ratings.
There is definitely an impact especially when the download and print counts get high.
Some. For some model designers who get featured and who have good models. There’s many more out there who may have good models but either aren’t striking a chord or aren’t featured where they get exposure.
For most who are trying to build income from this it’s small potatoes and the work is done on the cheap for way below market value.