Absolutely, though aren’t assist quality and defensive positioning both factors that influence xG and xGA? That’s kind of my thinking when saying why it’s a good metric.

It’s still probably the best, simple metric for assessing a team’s quality at a glance. At the end of the day it shows you how well a team creates goal scoring opportunities and how it prevents goal conceding opportunities, everything else is down to shot stopping and finishing (in theory).

I think it’d be mostly fair to say it shows who ‘plays the best football’, less whether a team is actually effective at playing football.