Who's preaching? Doesn't get much easier than this https://certification.ubuntu.com/desktop

Completely incorrect for Mac. At least for those that want their peripherals to work.

Correct for Windows. But then they just buy the machines and complain about their issues later, hence, this subthread.

The Mac comparison is better than the Windows one but Mac is in exactly the same position as Linux here: either you use the manufacturer recommended hardware (Apple hardware or the various pre-configured Linux laptops like System76) or you spend time looking up compatibility (Hackintosh/roll-your-own Linux).

The difference is that the manufacturer-certified hardware for Macs has a giant advertising budget.