Just noticed your videos are using old avc1 codec.
There is also a newer VP9 codec.It decreases pixelation in videos.
It automatically applies to videos on channels with many subscribers(dont know how many thousands).
But even if your channnel hasnt got enough subs you can get it.But it will require more space on your disk so that means longer rendering and upload.
It should force YouTube to use this codec when you render and upload videos in 2K resolution and maybe above some certain value of BPS.
it would not be an issue for me to render and store videos in 2k just it would be difficult to upload cause of my shoddy internet connection.
thanx for sharing that information anyways man