He is so insistent on this transfer request as he has witnessed what a scorer he is in the Premier League. The Tottenham president is making all kinds of excuses not to send Kane. If Kane wants to leave, there's no point in forcibly keeping him on the team. The same is possible for Mbappe. If he doesn't want to stay in Paris, they should allow the transfer of the player.
Indeed, at present the conditions of the two teams are almost similar to prevent the departure of their flagship players, but sometimes this will actually carve a bad view of them. I think as long as the player wants to feel comfortable and especially to be able to win titles it is worth making concessions. The champion league title is the highest above all existing titles and therefore every player wants it. Harry Kane and Kylian Mbappe are two top strikers who have never lifted the wide-eared trophy. Actually I want to see one of the two to lift this trophy with his new team later.