How do you evaluate how good a football player is? It is not as easy it seems. Two different people, both of which understand the sport innately, can watch the same game and draw different conclusions regarding the individual performances they see. It is the nature of living in an opinionated, subjective world. Humans think different things.
This is where stats enter the equation. The number of goals a player scores is not dependent on your opinion. Similarly, the number of saves a goalkeeper makes does not change because of your perspective. This is the point of statistical analysis: to provide certainty to a subject area that is inherently uncertain.