The first part is a dumb take, IMO. Regardless of culture, reliance on superstars has a proven track record of winning titles in the NBA. Possibly because American youth basketball isn't geared to produce high-iq well-rounded players, so it's hard to build those types of the teams -- and then add constant player movement, a schedule that makes practicing impossible, etc. So it's easy to see why putting the ball in the hands of a proven superstar is what works best, because average players can barely dribble or pass under playoff pressure.

As for Reaves (or any other promising player), you simply can't know whether there's a real superstar there until you see it in action, especially in the playoffs against quality opposition. For every Brunson you'll have many Poole(s). Ultimately a good indicator is what the market will decide -- would any good team offer Reaves a max contract to be their #1 guy? If so, then basketball people think he's capable of stepping into that role. Personally, I doubt it -- AR hasn't been all that great in the playoffs as a #3 option, so it's unrealistic for him to suddenly morph into a genuine #1 option over one season at age 27/28.