If/when support for Linux gaming becomes widespread and easy to navigate with few configuration hurdles, Windows will die very quickly. As for MacOS, I genuinely can't wrap my head around why anyone who is technically competent would prefer that OS.
The bastion of Windows installations will still be the corporate market. Outside of developer circles, Macs are only used by executives - the drones still get underspecced Windows laptops.
As far as macOS goes, Linux is so good but I also like my peripherals to work for my job where I don't have time to tinker all day.
Even technical users can succumb to Apple's Reality Distortion Field.