Here, this NYTimes article does a great job of expanding on the issue, despite it's clickbait headline.
Kill off everybody except you and another random person, and you have improved the odds of being better than anybody else from microscopic to a staggering 50%. Kill him or her too, and you're the best person on the planet.
Note that your odds of being the worst person increase the same way.
As far as I know, they've moved from large, free-build sets and over to smaller, less creativity-encouraging themed packs in recent years, the same way that Lego has. But the height of their popularity in the mid-90s was fantastic.