Gabe Newell made the pivotal decision to build Steam as a closed ecosystem where Valve takes a 30% cut of every transaction. With $30+ billion in annual revenue flowing through the platform, even a 13-15% net margin generates roughly $4-5 billion in value. Sid Meier, by contrast, created incredible software products—Civilization is a legitimate cultural phenomenon with 40+ million copies sold—but he's fundamentally a content creator operating inside other people's distribution channels. He built Firaxis as a mid-sized independent studio, which is genuinely impressive, but he's not capturing the same upstream economics.

The structural advantage compounds over time. Every new game developer, publisher, and player who uses Steam enriches Valve's moat. Steam became so dominant that competing platforms (Epic, GOG) couldn't dislodge it despite massive investment. Sid Meier's value is tied to whether his next game is brilliant—his fortune depends on execution and creative output. Gabe Newell's fortune depends on 30% of whatever anyone else sells. That's the difference between owning the movie theater versus owning the film studio.

There's also a timing and luck factor: Newell launched Steam in 2003 when digital distribution was nascent and PC gaming was fragmented. He essentially created an entire market category and locked it down before competitors understood the prize. Sid Meier arrived at gaming's peak but as a specialist craftsman in one genre (4X strategy), which, while beloved and profitable, never commanded the industry-wide leverage that a universal platform does. Both are legitimate moguls—but one owns the toll booth, and the other owns the toll booth tenant.