OP mentions that "I would love to be a little mouse and peek at YouTube’s complete architecture to see how far we are from them." You can occasionally find posts -often linked here- from another player in streaming video which you might have heard of, discussing technical architecture. For example, this might be a little lower level that you may be interested in as it relates to kernel optimizations to jack bit throughput rates, but I dig this sort of thing -
https://www.youtube.com/watch?v=36qZYL5RlgY