Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
My daughter wanted green socks for her birthday, so I ordered these from Amazon. They fit perfectly as expected, and she was delighted with the bright neon colour. And I am very happy with the price. Let's hope they last a few washes!