Have you heard of Charlie Munger? Most people probably haven't, which is part of why he's a great (male, real life) sidekick. Munger is the vice-chairman of Berkshire Hathaway and has been Warren Buffet's right hand man for decades. Munger is one of the examples in Michael Eisner's (former Disney CEO) book on partnerships. One of the book's main points is that 50-50 is a very unstable split in a business partnership, but if one of the partners is willing to stand half a step lower the couple can achieve more.

You see this example a lot in sports, and by "you" I mean me because I've met few rationalists who care about sports as much as I do :) Scottie Pippen would've been an excellent player on his own, but being Michael Jordan's sidekick made him an all-time great.

Since professional sports is very competitive and rewards "alpha dogs" with all of the money and fame (endorsement deals, max contracts, hottest groupies), players who could have been amazing Robins become mediocre Batmans. If players were only paid based on winning championships, I'm sure that would change. If your goal is to save the world, that's the only goal and no one cares about "individual stats". With this goal drawing quite a few heroes, being a sidekick may well be the best, noblest, and most effective way to contribute.