Quoting: Tintin
xG matters because it is a skill to be producing xG (and to effectively suppress xG, as a defender). Goals are a lot about luck and opposing goalies. Over the course of the last 15 years public xG% has proven to be better at predicting the outcomes for any given team over the course of a season compared to box scores, head-to-head etc.
Here’s a fairly informative thread on the matter. As long as you have a rudimentary understanding of probabilities and regression it’s an easily digestible read. https://twitter.com/bruins_analyst/status/1695980805313401224?s=46&t=MCqecojlL7qtwEDbOWTSzg
Then by all means, classify xG?
I get it's soccer, but it also applies to NHL: https://shewore.com/2018/10/09/xgs-why-it-is-flawed-and-pointless/
Goals aren't about luck, most times... Unless there's an unlucky bounce: https://www.youtube.com/watch?v=GRXtCFbQa3g but it's typically a goal executed to perfection: https://www.youtube.com/watch?v=P_PNoCW6HxQ