Its a very complicated situation IMO.
If you are Kane, you probably feel you have to go this season, age, demand and the like.
City may sign a replacement, that means next season they won't need a ST even if they do Haaland, Mbappe will be available for affordable prices (transfer fee)
If you look at it commercially, Levy will never get £120m again for Kane, this is the highest his stock is going to be, I would go that far to say that next season his value wont be more than £70m.
For Spurs, they are not getting top 4 with / without Kane, £120m will allow you to build for 2/3 season or keep Kane and the team will not be built.
But again, if they sign Kane, fans will be expecting the money to be used this season for signings, which you have to get right
Personally, I think its a very tricky situation for all parties.