I adapted this headline from a piece I remember The Onion running thirteen years ago. The Onion's excoriating 1997 article, entitled "High-Definition Television Promises Sharper Crap," lambasted the increase in TV resolution for doing nothing to raise the quality of the actual content itself. YouTube's recent announcement that they now support 4K resolution is easy to poke fun at for the same reason, given no one was complaining that the thing missing from YouTube (which already offers 1080p) is more resolution.
From a technical standpoint, this announcement means that RED footage can be uploaded and played back natively. Except absolutely no one has a display that's 4096 pixels wide, and the RED itself is actually only, what, 3.5k after bayer filtering? In my estimation approximately 0.01% of the population will actually be able to view 4K footage on their computer, much less be able to detect the difference. Of course, YouTube is doing this simply to show it's possible, not because people are actually going to use it; to flex their resolution prowess, YouTube has created a special 4K playlist. Here is one of their 4K example videos, about a surfer who mistakenly believes his surfboard is self-powered and does not require actual waves:
This is a good example of what I'm talking about, because an overexposed shot in 4K is no better -- and indeed, probably worse -- than an overexposed shot in 720p (you'll have to click through to YouTube to see the resolution options). In terms of things that are missing from the filmmaking world, "YouTube in 4K" is probably the 9,438,224th-most needed thing. Still, I guess it's nice to know it's possible. You know, for all those times you've got an 30' screen and 4K projector set up in front of a packed house, but forgot to bring anything to show.