> The iMac has a build-in screen which likes go bad from dust, as do the components inside.
First I've heard of this, but I guess it's a thing?
(I've got a 2015 iMac 5k with no such problem, but, ironically, my screen is blue-taped in as I'm in the middle of adding a larger internal SSD)
https://forums.macrumors.com/threads/did-you-know-about-dust...
https://hothardware.com/news/apple-class-action-lawsuit-dirt...