In what sense did Bale do more?
Bale in 2012-13, in Premier League games, was producing at the rate of:
0.6 goals/90, 5.1 shots/90, 0.1 assists/90, 2.3 key passes/90, 1.8 successful dribbles/90, 1.0 successful tackles/90 and 1.3 interceptions/90.
This year Kane, in Premier League games, is producing:
0.7 goals/90, 3.5 shots/90, 0.2 assists/90, 1.1 key passes/90, 2.1 successful dribbles/90, 1.5 successful tackles/90 and 0.8 interceptions/90.
So, Kane is a more efficient shooter (slightly better production, from over 2 less shots/90), makes less key passes, but dribbles and tackles more. And he is two years younger than Gareth Bale was in his final season at Spurs.
I fail to see how he is not comparable to Bale. Is he scoring highlight reel goals as often? No, but he is scoring as often (actually, more often). Is he winning us matches as much? Hard to say, Eriksen and Chadli have been stepping up as well. All that being said, Harry Kane is emphatically on the same level as Bale was in his best year for us. And Kane reached that level at a younger age, meaning he will arguably get better still.
Gareth Bale is not the best player Spurs have ever had, and we do have his equals among the current team as well.