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.
We bought two pairs of these boots. The first pair were too small for my daughter but returns and refund was easily sorted. The next pair we bought were the correct pair and my daughter loves them. She hasn't worn them in the rain yet (thankfully we've just had glorious sunshine) but they've covered plenty of miles through fields during lockdown. Would recommend these.