SpaceX does not stream on YouTube, you are watching an old launch on a fake channel. Please report them.
I tried signing up for twitter but gave up at the "match these dice with these symbols (1 of 10)" stage.
It's not a great interface compared with youtube etc, not rewinding etc, but at least it works
Looking at the SpaceX feed, they seem to be using whatever tech they got from the Periscope acquisition (at least the servers were still pscp.tv).
So take with that whatever it means, that it's just not going to be as first-class citizen like in Youtube. But the CDN etc must be good enough as those things are easier to do nowadays.
Then again you'd think one of Amazon's 1.5M employees would have the job of finding fake USB sticks for sale on the site, but apparently nobody has that title either.
This implies that YT has humans that are not in sales. It feels like YT just has bots building more bots at this point.