You've answered your own doubts in this post. Son not taking a shot twice in this game isn't the only time we've not executed a good opportunity. xG is a tool that should be used in conjunction with everything else, it doesn't tell the whole story, which is essentially what you're implying.Have to say I don't understand the "profligacy" narrative.
We've created roughly 10.3 xG this season and we've scored 9 goals. So we "should" have scored one more goal than we have.
The reason we scored more goals against Brentford than against Leicester or Newcastle wasn't because we were more clinical, it's cos we created much better chances (3.8xG vs Brentford). If anything we were just as wasteful as ever. Son was through on goal twice and didn't even take a shot, neither of which will have contributed to the xG stats.
If we're to consistently score more goals it'll come from creating better chances, like we did vs Brentford, rather than magically scoring 3 goals from 1.4xG produced as some people (and the manager) claimed we should have somehow done against Leicester.
It's interesting that you've omitted everything else I wrote in that post. Does this mean you agree?