I think there should be a distinction between winning and losing players/coaches/clubs. Tottenham hasn't won shit since forever, and they had great teams last decade or so. There is 3 domestic competitions and one european each year. Arsenal no matter how shit they are win the FA Cup regularly atleast. But then there is also overachievers and underachievers. Which of the two is Kane decide for yourself. I'll break down his career in short:
14/15 he scored 21 goals in the league and they finished 5th with 64pts. Weak competition tho, only Mou's Chelsea with 87pts and three 70+pts teams. They lost the EFL cup final to same Chelsea so that's fair. He didn't score. Lost in the 4th round of FA Cup to Leicester but without him. Lost in the EL Ro.32 to Fiorentina but he didn't play. So average season
15/16 he scored 25 in the league and they finished 3rd with 70pts, in a even weaker competition. Leicester with 81pts and Arsenal with 71pts. Losing the 5th round of FA Cup with him and many starters against Crystal Palace. Losing the EFL cup 3rd round against Arsenal with him playing. He didn't score in neither. Lost the EL Ro.16 to Dortmund, with him playing 24 minutes. So another average season but CL qualifications thanks to underachieving top clubs.
16/17 29 goals in the league, 86pts, 2nd place behind Contes Chelsea who won 93pts. 3 other teams finished with 70+pts and ManU with 69pts so it was a rather competitive season unlike past ones. Lost FA cup semifinal against Chelsea 4-2 and scored once. Lost the EFL cup 4th round vs Liverpool without him. Finished 3rd in CL group stage behind Monaco and Leverkusen with him scoring two goals, and then lost to Gent in the EL Ro.32 with him scoring once, but in the wrong net. It was 3-2 on agg. So other than the premier league rather average in other competitions.
17/18 30 goals in the league, 3rd place finish with 77pts, so a weaker competition again (City 100, Mou's ManU with 81, pool 75, Chelsea 70). Lost EFL 4th round vs WHU without him, lost FA cup semifinal vs ManU, with him. He didn't score. Lost to Juventus in Ro.16 of CL, 3-4 agg. Scored once.
18/19 17 goals in the league, 4th place with 71pts. City and Pool close to 100pts but Chelsea and Arsenal hang around 70pts. ManU 66pts. Was injured a lot of season and team played better with him out, except the EFL cup where they lost to Chelsea after having a 1-0 lead from the 1st game where he scored. CL they went on their biggest run ever with him out, eliminating a great City and Ajax side, then lost final with him back. Even vs Dortmund in Ro.16 they were better the game without him than the game with him. So asterisk season due to injury but also great team achievement in the CL without him.
19/20 18 goals in the league, 6th place. 59pts. Average competition, pool with 99, City 81, United and Chelsea 66 pts. Leicester 62. Another injury ridden season, and this time team didn't look better without him. Lost to Leipzig and lost both domestic cups. But team weaker than year before definitely.
20/21 so far 21 goals in the league, 4 games to go. 56 pts, 6th place. Average competition as we get at best 3 70+pts teams and City with barely over 90pts at best. FA cup lost 5th round to Everton, scored once. EFL cup lost final to City, didn't score. EL lost to Dinamo, scored twice.
With the NT, Euro 2016 zero goals, lost to Iceland in Ro.16. World Cup 2018 scored one goal (penalty) in the knockouts despite playing maximum number of games and every minute. Nations League lost the semifinal vs Netherlands and didn't score again.
Imo he's a talented CF but he hasn't shown it at the biggest stage. Most of the biggest games he played he went missing. So I'd rather pass on him