Is it true that we don't have a monoculture, though?

The author argues that algorithms have reintroduced monoculture: there was a period before the year 2000 when we had a monoculture (because of the scarcity of information) and a period after 2012 when we had a monoculture (because of effective information-sorting algorithms). The kind of cultural fragmentation you're talking about only existed 2000-2012, or in what he calls the 'hipster era.'

Post-2012, 'nerdy' things like comic book movies and gaming streams are basically mainstream to the point of being inescapable. People who remember the previous 'pre-nerd' monoculture are primed to think of those things as niche and marginal interests, but they're really not.