The reason I assume YouTube reviews are terrible by default is that literally almost anyone can do one. I’m sure there are good ones but they’re 0.0001% of the total because there’s zero quality control. And often when someone recommends some great video in here (or elsewhere) they turn out to be one of the 99.9999%. So while it’s wrong to assume every YouTube video is bad, the chances of being right about it are pretty solid.
(says this having not watched the most recent video posted)
If your ratio was accurate, nobody would go to Youtube.
I find a useful metric is 90% crap, 10% good.