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.
It's a hopeless product. Only ten metres each bundle instead of twenty metres and that too very thin. There are very good nylon ropes available in the open market. I feel cheated. The supplier should be blacklisted.