If Harry Kane goes to Real Madrid, it will be good for both Kane and Madrid
English players enjoy playing in their league not going abroad and he made it very clear that he wants to stay in London after he left Tottenham I think Manchester City is his new destination to replace Aguero since they will be needing a striker next season, man city are not the only team interested in his service Chelseal and manutd are also.
This is the same for almost all 5 major leagues in Europe.The good players in England stay in Premier League,the good players in Germany stay in Bundesliga and so on.However when it comes to Real Madrid being the club with the most Champions League wins for many players it is an honor to play for them and I think Harry Cane can find his missing glory(not winning anything with Tottenham) there.