Interesting that since the launch of 4K streaming the other day on Youtube for The Game Awards, I'm now able to stream 4K on my hardware and internet connection (with only little issues, at least in that live stream). I wasn't quite able to before, at least bandwidth-wise I think.
But... if you didn't record in it 4K, there isn't much point. Except that, for a year or 2 now, Youtube's new/current codec overcompresses 1080 and 720 so they really look like crap, especially at 60fps. The sad main benefit of upscaling to over 1080p is that Youtube gives you a (seemingly) reasonable bitrate or compression again.... Damnit, Youtube.
That was immediately apparent between The Game Awards the other day and PSX today. PSX's 1080 stream looked like complete crap and blocky as hell (and I'm still on a sub-1080 resolution...) Not a fan of Youtube making their codec worse for resolutions that most people are still at....