Most football statistics don't appear to handle positional play well. They don't handle managerial expectation for a particular setup. They don't handle a player that 'keeps things ticking' because those actions don't regularly result in particular trackable 'events' that modern statistics heavily utilize.
Stats work very well in American sports because of two things football lacks:
- Discreet events
Baseball is a series of discreet events. It is easy to quantify how each player handles individual events (batting with runners in scoring position against left handed pitchers, for example) because it is a discreet sport.
- Large sample sizes
Basketball works well with statistics due to large sample sizes - many shots per game, many passes per game, a small court.
Football doesn't have the same fundamental structure, and thus attempting to overlay American-style counting stats doesn't fit perfectly.
That doesn't mean stats don't have value - they do! But the value is, as yet, highly imperfect. And tbh, if they were perfect, there would be little reason to play the game - just run it through the sims.