"It takes some getting used to for most designers, though. They are not generally used to having their designs evaluated by their real-world impact. Remember that plenty of design organizations and design schools give out awards for designing products that never get built. So don’t hold it against a classically trained designer if they find split-testing a little off-putting at first.
[…] Teams that focus on optimizing can get stuck bolting on feature upon feature until the product becomes unusable. No one feature is to blame. […] When that happens, the solution is to do a whole product pivot. […] A whole product is one that works for mainstream customers. Sometimes, a whole product is much bigger than a simple device - witness Apple's mastery of creating a whole ecosystem around each of their devices that make them much more useful than their competitors. But sometimes a whole product is much less - it requires removing unnecessary features and focusing on a single overriding value proposition."