Basketball has a global appeal and that is mainly due to Jordan undoubtedly.
like you say and it’s a good point, you wouldn’t class say Bradman, Warne or Jonah Lomu as the greatest sportsman ever due to not enough countries participating seriously enough in their sport. To me exactly the same applies to Jordan and basketball.
Jordan is a phenomenon ,almost super hero like and a global legend but unfortunately for him the sport is dominated by one nation with no international stage to shine on. The 92 Olympics as great as it was, was in reality exhibition stuff.
To me, to take the title of worlds greatest sportsmen you need to dominate globally at international level against participants from all four corners of the globe.
I would suggest that the NBA is just that, it is the world stage where all the best basketballers in the world come together to compete against each other. The quirk with basketball is that you can't just have a stacked team of amazing players all on the same team as well, due to the salary cap. So other than Pippen he never really had that world class supporting cast that say a Messi or Ronaldo have to play with.