Exactly. A/B testing is very useful in some situations (i.e. where traffic to the page is great enough, product-market fit is achieved, and the product is well

Exactly. A/B testing is very useful in some situations (i.e. where traffic to the page is great enough, product-market fit is achieved, and the product is well-developed enough that any changes to it after the campaign is run will be minimal). But many companies, usually startups, scale too early and use the products poorly. Companies that sell these products have very little incentive to discourage use of their products by ill-informed users, so the misuse continues.