Had same quality issues - then just told YouTube to use 720p instead of auto-resolution and it got all better.
The NASA feed appears to be delayed by ~45 seconds from the YouTube feed.
Re:SpaceX Crew Demo-1 Mission [video]
by edvinasbartkus on Saturday March 02, 2019 @02:31AM
(#19288090)
but it is more delayed :)
https://www.nasa.gov/multimedia/nasatv/index.html#public