Comment by crabbone

The only reason I know ACPI exists is because every Linux laptop I ever had always spit a roll of error messages related to ACPI (and usually no support).

My understanding is that on top of the inherent problems outlined in the article, there's a more trivial problem of vendors not caring enough to do this right. So, typical for Linux laptops, hybernation and many other forms of power-saving either don't work at all, or are broken (eg. a laptop never wakes up from hybernation, or just the screen never wakes up etc.)