Hi!
I've struggle with YouTube compression several times... I do recommend if you can, uploading the video ni 1440p instead of 1080p.
If your footage is 4K you have no problem, if it's 1080p, upscale to get to 1440p would get you better results that uploading at 1080p because of the bitrate.
With 1080p you get a bitrate from 3.000/kpbs to 6000/kbps. If you upload 1440p you get from 6.000/kbps to 13.000/kbps
I've done some test and trust me, there's a really big difference!