I'll readily admit I'm a huge fan of Son. A few thoughts.
1. Everyone knows including Son and Kane, and especially Conte, that the team needed more production than from those two, so to go out and get the players they did was a necessary step
2. That Kulu and Richarlison are playing so well is exactly what Spurs need if they're going to challenge
3. Though Son may want to play every down (I mean every minute

getting rest is vital to getting more seasons out of a 30 year old player and Son should realize that
4. Getting pulled off as a starter is a lousy feeling and not a nice look on the screen, bench morale
5. Coming on and finishing as a difference maker and goalscorer/creator is not an insult
Hopefully Son maintains that chip on his shoulder, but none of us should feel sorry for him for what's really best for him