It allows optimizing many things such as the UX, the speed and size of your product, and your own time. Examples: * If you see that a button is used 10x than

It allows optimizing many things such as the UX, the speed and size of your product, and your own time. Examples: * If you see that a button is used 10x than an other button, you can re-order buttons. * You can remove buttons that are never used (=faster load times, less bytes) * You can drop features that are never used, focus on features that are often used, saving your own time. The other approach is "I already know what is best, I don't care about how other thinks". This is also useful because it can allow you to break out of local optimum.