[KozmoNau7]

Grading scales can work, for instance if people are rating and reviewing products in online shops.

You're looking at a jacket and you see that while some people rate it 5/5, most of the ratings are 4/5 and 3/5, and 85% of the reviewers say they would recommend the jacket to a friend.

So you read the reviews, and gather that most of the medium scores are because the arms are a little shorter than expected and the cut across the back is rather wide. You also notice that everyone is praising the quality of the fabric and worksmanship. Good information, since if you have short arms and the back muscles of a powerlifter, that jacket would probably be a good purchase.

That is good use of a scoring system, but it requires people to care about it and about writing reviews. It works for niche sites, but completely breaks down somewhere like Amazon, or on Uber/Airbnb where you get punished for anything less than a perfect score.