And the result is that users overwhelmingly prefer to use Steam, with alternatives largely relegated to at best grudging acceptance for those games that require alternative launchers. Since companies are reluctant to post numbers, it's hard to tell what the exact situation other than "Steam is well over 50% of the market", but the next largest is probably GoG, especially if you exclude self-publishing from statistics (if you include it, the popularity of Fortnite might push Epic Game Store into second place). And note that GoG is pretty much the only store that offers users a specific value proposition to use them over Steam: GoG is DRM-free (better publisher/distributor split is a value proposition for developers, not users).