I don't know where you got your numbers from but they don't appear to be correct. According to this, MacOS is around 16% while Windows is somewhere around 70%
Yeah, the worldwide data seems more relevant. Still, if you look at it, apparently Windows has lost more than 5 percentage points just in the last three months. It seems to be a historical low. I don't know what triggered this, but at least in the US, Windows seems to be on its way out. Though it could have also to do with Apple's very efficient M CPUs, which aren't available for Windows, not just with MacOS itself.
