That's seems the only logic reason for harry kane to stay in Tottenham, if he really love the club and want to stay even without winning titles because he love the club no one can blame him, but many football fans hope to see this player in a bigger club
It looks like Harry Kane would prefer to stay at Spurs for that reason and maybe it's okay for him not to win any titles as long as he's wearing a Spurs shirt. But sometimes if that's the case with other players, of course he has moved to another club a few seasons ago, but not with Harry Kane as if his soul is very much one with Spurs. But whatever decision he makes we have to appreciate it and if he starts to change his mind before the summer closes it will be better for his future to be able to win trophies with other clubs.
Some people argue that Harry Kane feels comfortable with Tottenham but actually this opinion is wrong and can be denied because last season Manchester City was very interested in recruiting this player it's just that Tottenham didn't want to let go we even heard rumor Harry Kane would not be serious in every game if it didn't go to Manchester City. The only reason why Harry Kane is still with Spurs is because they continue to hold it and offer a higher salary, in the last season Tottenham raised his salary to $200K-$300k per week and additional bonuses in every season.