Yeah, that's why we didn't have anything anyone could possibly consider as a "great product" until A/B testing existed as a methodology.
Or, you could, you know, try to understand your users without experimenting on them, like countless of others have managed to do before, and still shipped "great products".
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.
Or, you could, you know, try to understand your users without experimenting on them, like countless of others have managed to do before, and still shipped "great products".