> I have never understood what's the point of investing in such an expensive and new tech for videos for YouTube

these people are professional content makers. they make their living from buying/receiving gear and reviewing it on youtube. this isn't a hobby. youtube is big media now. very, very big. "just because you don't use it doesn't mean nobody else does."

if a film editor, or professional photographer, or rich guy, or web developer, or options trader, or magazine designer, or whoever is in the market for an 8k display and/or camera rig, they go to youtube and watch the reviews.

but in general... you know we used to have 640x480 screens and 20MB hard drives, right? that was 'normal', and 1024x768 seemed excessive. welcome to the forever now.