How do you define superstar?
Off the top of my head I would say that Chris Paul, Derek Rose, Kobe, Lebron, Durant and Howard are guys that mosti would consider superstars of this era.
How about Andrew Bynum? Many people consider him to be a better center than Dwight, yet somehow nobody really thinks of him as a superstar.
How about Russel Westbrook? Is he really a step below Rose as a player? I don't think so.
How about Dwyane Wade? He was unquestionably a superstar prior to Lebron coming on board, but now that Lebron is there Wade's numbers aren't looking any more impressive than someone like James Harden - who I would certainly not categorise as a superstar. Bosh is certainly not a superstar either, but many would consider him one when he was averaging 25/12 for a terrible Raptors team.
How about Rondo? You can very legitimately argue that he is the second best PG in the NBA. You can even make an argument that he is #1 because now that Kidd retired Rondo is now the NBA's active leader in career triple doubles - that's a pretty darn impressive feat. What it is that decides he is not a superstar - is it simply the fact that he doesn't average 20+ PPG? Because if that's all it is, the isn't that a little bit...shallow?
Back in 2012 when we took Miami to 7 games in the ECF, Rondo played like a beast that entire series, but he was never labelled a superstar. I can absolutely GUARANTEE you that if Boston knocked off Miami and won a title that year, Rondo would have come into 2013 with a superstar title under his name and he would have been seen as an undisputed top 2 PG in the NBA.
Often the 'superstar' title gets branded on people based on the context they play in. If you look at KG's numbers in 2008 he was averaging about 18/9 which (on the surface) few people would look at as superstar numbers. Even today many people look at KG and say he was on the decline when he joined he Celtics. Garbage - in 2007 (only one year prior) KG averated 24/14/6, had the best season of his career, and was voted the league MVP. Do people really think he went from the best player in the NBA to a mere 'All-Star' in the space of one season? No. His numbers dropped because of a reduced role and more sharing of responsibility, and superstar status always gets based on numbers.
Another example is Harden. He was a sixth man in OKC and was nobody thought THAT much of him, but then he goes to a comparatively average Houston team where he is the #1 option and suddenly he averages 26 PPG, and soon the superstar label will be thrown on him too.
Rondo was sharing the court with two superstars and a borderline superstar for most of his career and everybody points to that as a reason for his success. Once those guys go, how do we know he won't take on more of the scoring load and end up an 20/10/6 guy?
The whole superstar label is one of convenience I think. I don't belive you need a superstar, I believe you just need a group of very good players who complement each other perfectly. For example you NEED a player who can be relied on as a go-to scorer who can put 30+ points on the board on any given night. He doesn't have to be a superstar, he can just be an elite scorer - but you need that type of player to dig yourself out of big holes, to put away teams that keep climbing back, and to put constant offensive pressure on your opponent. You also need elite defensive stoppers who can STOP opposing teams from lighting you up. You need playmakers who can orchestrate a offense. You need a great 6th man who can bring energy and dominate when your starters are having a bad night. You need a second and third scoring option (i.e. Garnett and Allen) for those nights when your first scoring option (i.e. Pierce) is struggling. You need guys who can score inside to draw double teams and open up your shooters...and you need shooters who can scare the defense away from collapsing on your interior scorers.
At the end of the day if you have all the right pieces, you have every opportunity to contend for a title. Out 2012 Celtics team almost knocked off Miami and their three-headed monster and how many superstars did we have that season? KG was on the decline, Pierce and Allen were both hurt AND on the decline. Neither of those guys was a superstart at that point. Rondo apparently never has been, so in theory we had no superstars...but we challenged them to the end because we had players who played their roles well and who simply played hard.