They briefly mention literature and I think that provides a good counterexample. Books are highly individual, and always have been long before streaming existing. Yet, there still manage to be runaway hits that everyone reads and talks about. The same could be true of streaming shows. Stranger Things managed it in the streaming era.
The 80s is an interesting funnel for shared monoculture. Modern enough to be relatable today, distant enough to serve as a canvas to project all sorts of personal bias onto.
Personally I love the 80s lore and I think I loved the 80s as it happened as much as anyone can love something while still being inside it. It was just so palpably on the verge of so many things, the Cold War ending, (violently or peacefully, it was obvious it was going to end!), technology promising so much without the downsides being a reality to deal with, and the downsides projected in dystopia sci-fi were still cool downsides, not the mindnumbingly dreary, boring dystopia we create for ourselves now with FB, China and its ilk.
While it's a good idea, at least for now I think the technological differences disrupt the parallels. For books, the only capital/tech barrier to entry is the singular entity of the book itself. The object of the book carries a complete copy of all the requisite information and a human interface for it with no further infrastructure requirements at all. It can additionally be read, than shared, sold, etc., with a life time of decades or more.
But at least for now, streaming shows are inherently silo'd. You must have a subscription at some particular service, and there aren't any real "meta-service" bundles either which makes it fragmented even compared to something like cable. They're ephemeral, harder to trade around, etc. It's a significant amount of friction vs a book isn't it? If there is buzz and word of mouth about a book, anybody can simply go and get a copy for the one-time outlay of that copy, or borrow one from a friend/family, or for that matter go to the library (we have an entire public service dedicated to free availability!). But if someone tells me about a great show they watched on a service I don't subscribe too, well, it's probably not going to be enough to get me to sign on. I'm feeling pretty sub'd out. Maybe I'll go check a torrent site or something, but maybe not. I can't just tune in on that channel and check it out, or duck into a book store and read the first chapter then grab it or not.
Books (and other low capex media in other countries for that matter) do show that huge culture-wide hits can emerge organically from enormous diversity and niche. But I wonder if the higher the technological barrier to entry the harder that is. It might be hard for it to happen without more cooperation between services, meta-services, a reemergence of some utterly dominating service/monopoly, or a legal imperative for interoperability or cross licensing after a delay.
Books are incredibly cheap to produce, so it's way easier (as in: less risky) to produce stories for niche communities through books rather than through movies.
