When NBA players are ranked by their career average rebounds per game, only one of the top twenty players is active today. That is Rudy Gobert and he ranks #20.
When NBA players are ranked by their career average scoring per game, eight of the top twenty players are active today. Those eight players are Doncic #3, Embiid #4, Durant #6, James #7, Young #12, Lilliard #13, Mitchell #18, Curry #20.
Both rankings include only players who have played a minimum of 400 games.
Chamberlain is #1 on the rebounding list and #2 on the scoring list. The only other players on both lists are Elgin Baylor #5 scoring and #9 rebounding and Bob Pettit #10 scoring and #3 rebounding.