Whilst you have a valid point, it's worth remembering that Kane had a low conversion rate, particularly when compared to Son.
Eh? He was 7 goals ahead of xG last season, which other than Son I assume was the second best in England. The only season Kane has ever been even on xG was the Nuno & Conte season. Generally he’s exceptionally clinical, this season unerringly so.
Son is an outlier in that he’s mind-boggling good at getting more than he’s expected to. Possibly the most clinical forward around.