What OS is better for gaming?

Windows, by far, has the most hardware and software support for gaming. Windows also has DirectX 12. While Linux has made great progress in recent years with becoming more useable for gaming, it's still not able to be as optimized as Windows for performance, graphics, and hardware support. Even Valve's SteamOS (a Linux OS) which was designed specifically for gaming regularly underperforms on nearly all benchmarks in comparison to Windows, by a significant amount.