Good Capture Quality | Poor Final Render

A short test video to see if I can get a HDRP scene to film. In the game engine, and with the capture (individual still images in the sequence), everything looks great. When I go to mp4 (1080p), I seem to lose quality. I could use feedback on how to fix a couple of things.

1. When the camera is moving fairly quickly it looks pixelated.

2. As the cameras move, trees and various things suddenly pop into view, rather than having them in view the whole time.

My initial thought was maybe a far clipping issue with the virtual cameras so I adjusted the distance a little, but it didn't have any effect. Any suggestions would be great, thanks.

Test Video

Update: Actually, I'm not sure I do have quality loss. When I play on YouTube it doesn't look very good; washed out and somewhat blurry here and there. When I play the same file on my local machine it looks great. Except for what seems to be a clipping issue during capture.

Update 2: I understand the quality issue now. The mp4 file is not the problem, it is the codec on YouTube that is causing the issue. Now I understand it is important to get the vp09 codec and there are a few ways to make that happen.

Test Video with vp09 Codec