I love, love, love Kane. I think he would be transformative of our squad and make us into genuine challengers on all fronts. However, Mbappe is a generational talent who is 24 years old and probably would win a couple of Balon d'Ors if he went to Madrid. We would be signing the future balon d'Or winner if we got him. He's technically superior, a force of nature on the pitch, and can influence games by sheer willpower. Player v player I think Mbappe is the better option.
However, raw ability isn't everything, and the circus that comes with Mbappe, the fee, the wages, the publicity chaos and everything that comes with signing Kylian Mbappe is a huge negative. I would much rather have Kane, a reliable player who fits the system and is a model professional, than Mbappe. Kane costs less and likely has a less absurd wage demand than whatever we would need to pay Mbappe. Mbappe is currently paid €72M - or £1.1M a week, and is being offered the equivalent of £11M a week by Saudis. In addition Kane has a tremendous record in the Premier League and a consistency that few others can match. He would slot in perfectly in the squad we already have, while Mbappe might need quite a few adjustments - most notably he plays at his best in the position of our current best goalscorer Marcus Rashford. When you add it all together then Kane is the better option for us in this current point in time.