It's entirely subjective really, always has been. It's whether in your opinio you consider him to be the best player or the best footballer. Personally I think he's an awesome striker, great finisher, has great movement, finds space, dominates his opponents with ease and he works hard for the team. The problem is, he plays for City and there's just nothing likeable about him.
I'd consider KDB as one of if not the best football players in the world, he might not be the best player, but he's ultimately a much better footballer than Haaland. Even Mbappe, Benzema are better all round footballers than Haaland.
Haaland is the best goalscorer at the minute. It's just like what Ronaldo did at Real when he was winning the Ballon D'Or. Still people argued over who was better, him or Messi. Even though Messi all round was and is a much better footballer overall.
If City win the CL, then he'll probably win Ballon D'Or this year or whatever it's called now. Still people will say that he's not the best player in the world.