He's not finished, and it is a legitimately arguable question which of the two is the best player right now. Kane is certainly more well-rounded (as he should be, at 27). On the other hand, he doesn't match Haaland in some areas of the game, and Haaland has significantly outscored and outperformed him in the CL over a long stretch of games.
Personally I might favor Kane in the short run, but if you poll 100 football experts on who's the best player right now and ask me to place a bet on the outcome of the poll, my money is on Haaland.
Long term, I don't think there's any question who the best option is. Not just because Haaland will be great for a longer time than Kane simply because he's younger, but also because you'd expect his peak level to be higher than Kane's.
Also, some consideration should be given to Kane's recurring injury trouble the last couple of seasons, including for the issue of short term impact.