Earlier quoted context omitted.
The thing is - a lot if power saving is achieved by hybrid sleep (computer hibernating after a timeout). Setting that up is pure hell on Linux, with poor documentation and security people actively fighting against making this easy. On Windows/macOS it just works, on Linux you'll probably break secure boot with it.
Maybe it just works on MacOS, but it's prone to all kinds of breakage on Windows.
BIOS support for proper hibernation has been getting worse too because with MSFT demanding it, there is little reason to continue support.
I've had older laptops that do the sleep->hibernate setup without too much issue but now it is a crap-shoot on if it is even supported in the hardware.