Boruto wants to surpass Naruto, but we all know that without some huge asspull that's not going to happen. So maybe what kishi means is that Boruto will surpass just "Naruto" and not Naruto with his handouts. So Boruto will be stronger than Naruto if he didn't have bijuu and rsm.
Maybe we'll get a scene in the future where Naruto says something like this "Boruto, i'm proud of you, and you should be proud of yourself, you've reached a level I couldn't even dream of without Kurama's and the sages help."
This, to me, is a happy medium. Boruto "surpasses" Naruto but accepts the fact that he can't be stronger than his father, but he realizes that it's something out of his control and by him accepting this we see growth in his character.
Maybe we'll get a scene in the future where Naruto says something like this "Boruto, i'm proud of you, and you should be proud of yourself, you've reached a level I couldn't even dream of without Kurama's and the sages help."
This, to me, is a happy medium. Boruto "surpasses" Naruto but accepts the fact that he can't be stronger than his father, but he realizes that it's something out of his control and by him accepting this we see growth in his character.