This seems to be key. People must want Windows or Linux so badly they will pay 25-30% for a thinkpad with a track pad that is almost as good. Don't these manufacturers sell more machines than Apple and could benefit from better economies of scale. Maybe the scale is just at the low end and the iPhone subsidizes premium Mac hardware.

I have yet to read about someone who priced out something "as good" as the MacBook Air in terms of component quality and efficiency. What would the price premium be... over 50%?

Either way it costs money to avoid macOS at the higher end but not much when you’re spending thousands of US dollars.