There's usually only about 5 superstars at a time. Between LeBron, Durant, Davis, Curry, Harden, Westbrook, Cousins, Chris Paul and Kevin Love, you can probably find 5 guys worthy of the label. There are several quality young players on the rise throughout the league.
LeBron would be a superstar level talent in any generation. Anyone who undersells his ability doesn't get it. That guy is otherworldly.