I reinstalled Ubuntu on an Asus that shipped with Ubuntu, and wireless randomly doesn't work on boot. Claims that it's disabled by hardware switch (there is no hardware switch.)

Suspend works fine now in my experience, it's mainly hibernate where the remaining issues are.

Interestingly muy suspend/resume worked always for 3 different computers, but failed on one desktop.

Agreed with this. It's why I still run Windows as a host and Linux in VirtualBox instance.

If you run it the other way round, the battery life is half.

(that is with powertop optimisations and a fair chunk of other optimisations as well)

I can't speak for hibernate/suspend, as this has worked well for me on every linux laptop I've owned (first one in the mid-2000s).

For WiFi, many (most) vendors simply refuse to provide open source drivers, which hinders inclusion in the kernel. The blame here is almost entirely on the hardware vendors.