I use a Linux distro with kde, so I have a lot of customization available. I like trying other distros in VMs, but stuff like windows (no need to copy really kde is similar by default) and Mac is a pain in the ass to use that way. so, I want to know what your os does that you think I should copy using kde's customization. I'm looking for Mac in particular (bc I haven't used it before) but any OS or desktop environment is fair game.
It is gnome, but https://aylur.github.io/astal/showcases/ is pretty awesome if you've done any React development. Pretty much coded up my own desktop environment with typescript and tsx for layout stuff. Lot's of fun widgets.
Note that I use nixos so pretty much everything is hand picked instead of a prebuilt ready to go environment. Hyprland for the basic desktop, Astal for my desktop shell with widgets, toolbars, etc.
Pretty snappy. All the gnome APIs are written in C. It doesn't run on node, it runs on gnome-javascript (gjs) which exposes all the C APIs through JavaScript. If you use the Astal wrappers its pretty painless but using the gnome APIs directly in gjs is a little weird since you have to consider things like memory management.