I am guessing this thread is yet another hoop thread comparing eras without allowing for consideration how, for example, Kareem in today's world would be different than the Kareem in his day. The training and skill development is incredibly different. Kareem had the athleticism to defend ball screens. Worthy's range would have been a step or two greater, at the very least he would have developed a reliable corner three. Pick any great player from the 80s and try to imagine them coming up in today's basketball world of specialized training and development.
It is so lazy, and stupid, really, to compare eras without this type of allowance.
Bird was, arguably, a better athlete than Luka Doncic. Watch Bird in the early- to mid-80s. This crap about him being "average" athleticism is bullshit. He was 6' 9" and played wing. There is more to athleticism than dunking. There is hand-eye coordination. There is agility and footwork. There is body control. Throw anticipation in there. Now consider Bird in today's world, with today's training and skill development, with today's attention to detail regarding diet and nutrition, sleep and recovery.
Today's game suits Bird more than the game of the 80s. Bird's skill and understanding of the game, his sense of space and the moving geometry of the game, pretty much every skill he possessed would likely fare better in today's game with its increased spacing.
Also, today's game is all about team defensive principles, about rotations and anticipation of rotations. Defending ball screens is essentially a two-man zone with a three-man zone behind it. Contract–expand–contract–expand. Bird was a great help defender.