Do you think our good old friend Dom Solanke's finishing has improved or is he just getting lucky? His xG has always been high, difference is he is now hitting good numbers because he has improved. To put it down to variance or anything similar is nonsense.
That's the point that's been made. Players tend to average out to their XG because finishing as a stat is negligible and down to variance. What is more important is getting in the right place at the right time. Solanke has been doing that and now it is paying off. Watkins has improved it and now he is scoring more.
The act of finishing is hitting the ball in the right direction, and most professional footballers can do that at this level. Whether it goes in or not is sometimes not what you can control (miss hit, goalie saves, bounces off the bar).
You have good XG you'll have more chances, eventually it starts paying off, and you end up scoring about what you were expected to.
Solanke himself is proof of that - it was always good, now he is scoring.
It's more important to regularly be in the right place at the right time