Evo jos informacija:
It's because since sometime in 2016 when you upload a video which is 1080p or below, youtube uses avc codec instead of vp9, which looks messy, crappy, pixelated,blurry when lots of motion ongoing in video. You can check it by right click on ur youtube video->Stats for nerds To get your video encoded in vp9, your channel needs some popularity that meet the certain requirement, so all your video will be encoded in vp9 permanently. Or your video needs to beat least 2k (1440p), so if you have 1080p or lower resolution videos, you need to upscale them to at least 2k, for youtube to encoded your video with vp9 codec, avc vs vp9 big difference, vp9 looks so much better.
Probacu sad caku sa Edit-Enhacement i onda Save. Trebalo bi kao da prebaci u vp9, posle procesovanja. Pa cu videti da li ce to upaliti.