The league if finally diverse enough that they could maybe do US vs. the World and come out ok, but it would change the way they vote for All Stars and I don't think they want to do that. It also might mean a few much lesser players make the team over much better players, which would be very problematic. This is true because while the World is stacked with big men (Giannis, Embiid, Jokic, Siakam, Porzingis, Gobert, Towns, Ayton, and several others including Sabonis who might make the team as Indiana's sole rep) outside of Doncic, Simmons, Murray, SGA, and Hield there aren't many guards or wings worthy of even being considered for the All Star team (and to be clear Doncic is the only one that is a clear all star). I mean are you putting guys like Dragic, Ingles, Rubio, Bogdanovic, and Wiggins on an all star team (or some much lesser American big man because you need someone on the team while leaving off some pretty solid world big guys). Maybe when (and if) guys like Barrett, Markannan, Anunoby, etc. hit their full potential it might make more sense.