If I had to guess it's because Apple controls both hard- and software. Sleep is a delicate business where both the OS and the hardware have to work together to get it right. Linux and Windows run on an endless combination of different hardware components whereas Apple knows exactly on what hardware their OS will run.

And in true macOS fashion it only works if you stay within the Apple ecosystem.

Applications and sleep are intimately tied to native macOS workspaces, which are themselves cursed af.

If you use an alternative manager, like Aerospace (which reimplemented workspace/tiling), then applications cannot sleep properly, leading to severe battery drain.

https://github.com/nikitabobko/AeroSpace/discussions/1008

Same with my Arch install btw, suspend works fine. 🤷‍♂️