Recent testing revealed that Arch Linux, Pop!_OS, and even Nobara Linux, which is maintained by a single developer, all outstripped Windows for the performance crown on Windows-native games. The testing was run at the high-end of quality settings, and Valve's Proton was used to run Windows games on Linux.
As pointed out, in Windows defence, it’s actually faster where it matters. And none of it is going to matter in adoption until every thing is supported 1-1.
The only reason we’re behind on adoption vs Windows as this point is that people who write software for Windows, don’t do it for GNU/Linux, or even publish specs in the case of drivers.
It’s not the OSes problem. It hasn’t been for a long time. It’s stubborn developers (mainly corporations like Broadcom, Nvidia and Epic). We shouldn’t need to write compatibility layers for completely foreign software to run, or write drivers to drive a megacorporation’s hardware, and those are both a monumental task, but the community continues to achieve it anyways.
A lot has been done and continues to be done by the community, and that’s great, but the real problem is the corporations who refuse to invest a little bit of their time in GNU/Linux support (and those who have an irrational vendetta against it).
Causes don’t matter. Only the reality. Incompatiblies and crappy lows will keep adoption low.
Causes are a part of the reality. And when people go online and complain about how “lInUX SuXxx” because their proprietary Nvidia drivers didn’t work, and blame the OS instead of the company who is meant to be providing proper support for their devices or at least documentation for other developers to use, it plants the idea in people’s minds that the OS itself is simply inferior, which has connotations of it just being a bad system. Instead of “it will work perfectly when drivers are actually released by the manufacturer”. It tarnishes it’s reputation even after that particular device gains support, and that is another reason why adoption is low.
Hell, nVidia was actively working against having a working opensource driver reverse engineered by Nouveau. Linux is a thorn in their side and the only reason they somewhat support it today is that GPU compute works so much better on Linux.