I’ve found Mac OS to be snappier than any of the dozen or so Linux DEs I’ve tried. I use Fedora with XFCE and it’s ok in responsiveness, I’ve got PopOS on another machine. It’s good. But I’ve got MacOS on my other two machines and they just feel so much snappier. And the Macs are 6-7 years old. The other machines are newer (2/3yo).

For Windows, my last experience on a personal install was Windows 10 and that was yeeeaaars ago, so... Grain of salt :)

It's not the default, but IIRC Windows could be configured to have zero animations, and I found it to be quite responsive as such.

I'm not talking about the speed of opening programs, but more of the speed of every-second interactions: Unfolding a folder (or other interactions within a program with keyboard or mouse), alt-tabbing across windows, moving between desktops, etc. At least on Windows, I saw far fewer IO-blocking animations than I have on MacOS.

You're right about the "something starts to happen": Apple hides delays behind sigmoidal animations throughout much of their OS. For those who aren't aware of the trick, the delay between the start of the animation and the tail where it starts appears to just be an animation that started on the interaction.

Windows isn't a useful base of comparison anymore. They really stopped trying years ago.