Of course tiny factors can affect football matches, that is why stats people look through to the underlying factors where there are far more observations, which then reduces the luck factor. Instead of goals, you look at shots, you look at shots on target, you look at shot quality, you look at how the chance was created, and you don't look at 1 game, you look at hundreds or even thousands of games. Then you can get an idea of which teams may have been lucky or not.
As for their use, they help you understand what is happening at the basic level of the game, and a lot of people looking at them will be using them for prediction, ie betting or fantasy football.