If it is ANY data that has to have human input at the start to work out the math, then it is subjective & therefore completely pointless.
But that's not the point in this instance. We are performing above XG and as you point out have been for some time. I'm just observing that one of the reasons for this probably is that we have the best keeper in the world.
To me, the great thing about Xg or xG, whatever it is, is that you can be poring over it like a 13 year-old who has found some hedge porn or you can, understably, completely ignore it and simply enjoy/suffer the football. ;-)
You can argue that XG is irrelevant all you like, but it is a stat used worldwide as a performance indicator and I'd imagine clubs data analysts look at it when assessing players even if you don't. But that's not the point in this instance. We are performing above XG and as you point out have been for some time. I'm just observing that one of the reasons for this probably is that we have the best keeper in the world.
, I just fucking despise xG & think it is a worthless tool.