Of course it's an outlier. He's doubled his xG. So it absolutely hasn't been par for the course. Re Nunez, I just don't buy the idea that one season is an outlier but the others are 'him'. The reality is that players underperform and over perform their xG in different seasons but it mostly reverts to the mean. So it's best to take the largest sample size possible as representative. And if his one season of overperforming his xG is enough to cause him to be basically hitting his xG over his career guess what, he's not undershooting his xG by very much. And of course, even if you think he's mostly going to shoot under his xG you still need to accept natural variance and luck - see the number of times he's hit the woodwork this season and reckon with the possibility that he might overperform in future seasons, as he over performed in a past season.
People just need to stop under emphasising the ability to get high value shots and over emphasizing finishing ability and we'll all be a lot closer to agreement. I doubt we'll agree in every particular but at least we won't have insane ideas about Nunez being rubbish in the face of actual production, which is genuinely really good even with his bad (and unlucky) finishing.
So Jota being over his xG this season is definitely an outlier despite him doing very similar before, but the season that Nunez outperformed his xG wasn't, despite that only happening for one season in the past five? I'm not getting into the bulk of the other stuff you wrote as it largely consists of intangibles that can't be properly measured such as 'luck'.
And what is this?: " his one season of overperforming his xG is enough to cause him to be basically hitting his xG over his career guess what, he's not undershooting his xG by very much".
So, it's ok that he's underperforms his xG almost every season (4 out of the past five) because he had one really good season, so it all evens out? That's not how it works.
Incidentally, do you have somewhere that I can see the stats for "high value shots"? All I am able to find is total shots on goal. As far as that goes, Nunez has the highest amount in the league with 104 shots, but only has 11 goals, which other players in the league have managed with around 40 shots on goal. This appears to indicate that finishing ability is more of a factor than you give it credit for. I am not suggesting that total shots aren't a factor
at all, but of the top ten scorers in the league eight of them are above their xG (Salah is slightly below his as is Haaland for the first time ever) and every one of them has outperformed their xG for multiple seasons. That indicates that finishing ability is not overemphasized as you claim.
The problem with Jota and Nunez regardless of how xG-savvy you can be is that you can see with your fucking eyes who has better technique and who can strike a ball more cleanly therefore is the far better finisher lol.
...and of course there's that too.