There is a wealth of info here
https://theanalyst.com/eu/2021/06/what-are-expected-goals-xg/
The database claims to have data from over 2.5 million shots from over 66,000 players, presumably from the top leagues.
Whilst I agree that strikers in the premier league should be better than those in the EFL I would also expect the goalkeepers and defenders to be better too, cancelling out that benefit. I’m assuming that for every Kane or Afobe that there would be multiple players in between with ‘average‘ ability hence saying most will be near average. With the xG : goals ratio from players last year in the championship it appeared fairly clustered around the mean / median.
I do agree that trying to assess a player like Pearson with xG is absolutely pointless. But if we want a quick stat to see if a result was a fair reflection of the game then xG might be the best we have. It is more nuanced than shots as this does not distinguish between pot shots from range and ‘sitters’, big chances are subjective too and who sets the threshold for the big chance, and possession is flawed. We could just focus entirely on the score, but Id imagine we’ve all been to 2 games where the score was the same but in one it flattered us, but the other flattered the opponents.
The timeline does show you at a glance how the game panned out.
All this said, I’m not trying to persuade anyone to look at these if they think the analyses are flawed. Hopefully though, there is a proportion who find it interesting when viewed with a critical eye.