Aaand even within desktop space IIRC it originated in Apple ecosystem and then appeared in couple of places, for example in Hyprland and (correct me if I’m wrong) in Caelestia-shell, I don’t think microsoft has it though…

I think it’s a nice visual effect and is underrated.

Yes, but it’s also a known term outside of microsoft:

(mathematics) A closed curve having properties intermediate between those of a square and a circle.