Didn't notice a whole lotta blur there, but then given the simple graphics the game has and your tendency to constantly shake back and forth, it wasn't exactly easy to look for it either.
At any rate, the problem lies with YouTube. It allocates only 1/3 to 1/4 the processing bitrate to 1080p uploads that it does for 1440p. You used to be able to get around that by resizing your vid to 2048x1152 while compressing it, which tricked YT into using the same bitrate it does for 1440p. Now you have to resize to 2560x1440.
I know that sounds insane, as 1440p is about 78% more pixels, and resizing to that res without all those pixels to support it you'd think would look blurrier. Since you're getting 3 -4 times the processing bitrate on YT though, it more than makes up for it.
Here's a comparison of what a 1080p upload looks like vs a 1440p of the same level of GRW.
1080p Version
1440p Version
Note that YT recommends a bitrate of 12,000 for 1080p vids, but no matter how much higher you go, it will not make use of it. For 1440p they recommend 30,000. It matters how much detail the game has though. GRW has tons of ground foliage detail that can start showing pixelation when moving over it. I was able to use just 20,000 on The Evil Within though, and it came out looking great.
The Evil Within 1440p @ 20,000 compression bitrate (note how even the fog doesn't show pixelation)