Youtube is very different than Netflix from a technical problem perspective. They serve free videos to anyone around the world that are uploaded by users.
It's closer to a live streaming problem than pre-encoded video like Netflix.
Having worked at Netflix I can say that the YouTube problem is much more complex.
I wonder what portion of Youtube's request traffic can be served with cache servers at the edge with a few hundred terabytes of storage. There's a very long tail but i would guess a significant portion of their traffic is the top ~10,000 videos at any given moment.
There was a Google organised hackathon on this topic. Given a set of resources, locations, and (estimated) popularity, Optimise for video load time by determining what should be moved to the cache when and where.
It's closer to a live streaming problem than pre-encoded video like Netflix.
Having worked at Netflix I can say that the YouTube problem is much more complex.