Well, let's look at NBA teams that have won without a superstar/'Top 67' player...
I expanded the NBA's Top 50 at 50 list because it came out more than 20 years ago or so, adding players rather than subtracting and adding to the top 50. I came up with 17 more. So the next 17 for me would be the following:
LeBron James, Steph Curry, Kevin Durant, Chris Paul, Steve Nash, Kevin Garnett, Paul Pierce, Ray Allen, Tim Duncan, Dirk Nowitzki, Reggie Miller, Dwyane Wade, Tony Parker, Russell Westbrook, James Harden, Jason Kidd, Dwight Howard...
Last team to make a Finals without a Top 67 was... the Detroit Pistons in 2005.
And the last team to win without a Top 67 was those same Pistons in 2004.
But that team had All-Star players having career years (Ben Wallace, Richard Hamilton, and Chauncey Billups), one freak who could have been an All-Star if he felt like it (Rasheed Wallace), a great coach (Larry Brown) and a completely dysfunctional Lakers team to beat in the Finals...
Maybe the 1978-79 Seattle Supersonics. But they had one player better than anyone the Raps have this year (Dennis Johnson) and two really good players (Paul Silas and Gus Johnson). They also played a team that had beaten them the year before, the Bullets, which had two HoF/borderline top 67ers of its own (Wes Unseld and Elvin Hayes were on the top 50 at 50 list) but not much else.
Um, that's it.
Even teams that make the Finals without a superstar are rare.
Even the 40-42 Houston Rockets of 1980-81 who lost to Bird's Celtics, the only Finalist in NBA history with a losing record, had Top 50 Moses Malone in his prime. The Portland Trailblazers, who lost to the Bulls and the Pistons in the Finals in the early 1990's? Clyde Drexler was a Top 50 at 50.
So yeah. Top-heavy league.