I think it relates to how their internal structure is set up and their brand positioning. Apple has only one design team and design system I think, and only caters to folks who prefer simplicity over power features.

I suspect that Windows is more like compilation of what different teams produce at MS, each with their own design opinions and target audience.

I can only imagine how challenging it is to serve beginners and power users with the same UI at the same time in Windows, which kinda implies different UI densities depending on the part of the OS or type of widget.

Apple has the advantage that they get away with simplifying things and have built a brand image around being easy to use.