Because they are signifcantly better players?
The league is about that stuff for roleplayers. Not for James Harden, or Lebron James, or Russel Westbrook or... Roleplayers don't stop the ball. Their job in fact is to move it along until they get it to the stars.
Rudy is of course closer to the line where that grows appropriate, and thus the questions about his game. He's an 18-20ppg scorer, not a 25ppg scorer. But he is a high level 1 on 1 scorer. having him play like a roleplayer isn't actually making best use of what he can do.
Casspi's development of a deadly 3pt shot has made him immensely more valuable than he was, but if you don't have that, and obviously very few do, the whole roleplayer thing is just an invitation to disappear into the background. Whatever Omri's secret to magic mid-career 3pt domination is, wish he would pass it along to a few. Probably better job security if he does not though. He's obviously approaching perfect Cuz support player at this point.
Significantly better teams don't stop the ball. Hawks, Celtics, Spurs, Golden State - it's all about movement for these guys. Of course every team has one or even two guys, who handle the ball most. No problem with that. That's why you have certain corner stone players. But those players make way quicker and better decisions, than our corner stone players and won't stop moving around once the ball leaves their hand. Curry f.e. is great when creating his own shot, but doesn't rely on it all the time. He will find his shots with off the ball movement alone.
IT changed his approach with the Celtics quite a bit. The pullup 3's and ill advised selfish shots are still there from time to time, but to me it looks, like he is playing way more within the team concept, than he did in SAC.
You could make way better use of Rudy Gay, if you would use him more in a finishing role around the rim and in the mid-range area, when all he has to do is to catch the ball, maybe take one dribble and score with this nice high release jumper he has. I think we played him this way this season in a few games and those were mostly very efficient games from Rudy.
Most of the time when we use Gay with a live dribble around the 3pt area, it results in a clunky dribble and a forced shot or drive, while everyone on the team stops moving and watches him go.
And DMC could improve his efficiency too, when he would cut those forced 1vsx drives out of his game.
Is this all on the players? Now I don't know about that. Coaching may be a huge factor in that.
And btw. with the way certain teams are playing, it may be a debatable point, if this league is becoming more of a "role player" league. Star power won't hurt, but you can have success in terms of reaching the playoffs even without stars and the stars able to play within a system usually win. "Give this guy the ball and he win's it for us" may not be the most efficient strategy today.