I know this is a salty take, but reliance on A/B testing to design products is indicative of product deciders who don't know what they are doing and don't know what their product should be. It's like a chef saying, I want to make a pancake, but trying 50 different combinations of ingredients until one of them ends up being a pancake. If you have to test whether a product works / is good / is profitable, then you didn't know what you were doing in the first place.

Using A/B tests to safely deploy and test bug fixes and change requests? Totally different story.