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.
The quality is really reallyyy bad. It feels and looks very cheap. They are like plastic, very flimsy, glitter comes off. Not at all recommended. If you’re looking for good quality nails but of “kiss nails” they are really good. I always get them.