Looking at etsy or the long list of artists on Spotify putting out music without hitting the mainstream radio, I'm not convinced the world has converged everywhere. I have far more variety that appeals to me available to me than ever before - and so does a person with opposite tastes.

Expensive to build or change things have - houses or cars - but art or more commodity products have fractured.

The people/media one is the author's biggest blind spot here: there is still a dominant mainstream that people are chasing, but it's audience is smaller than before. I think this is why they chase the same thing more aggressively. So your "bestsellers" look alike, but more people are reading random shit that would never crack that list in the past either. Selling to a niche is precisely the opposite of what gets you in the bestseller list, but the niches I like have SO MUCH STUFF available now. The non-mainstream has fractured, making the remaining mainstream look more similar to chase a narrower segment. The most watched TV shows now have a far lower percentage of the country watching, and also have more variety in what the cast as a whole looks like, whether that's hairstyle or tattoos or piercings or whatnot.

EDIT: here's an experiment to try to demonstrate. Tell me how many of those lookalike movie and book poster/cover images you've watched. And how many you'd watch more of.

Movies: I've seen 0 of those (I'm not a horror fan anyway, but I've seen a couple in the last five years, Hereditary and The Invisible Man, and they didn't look like those posters).

Self-help books: I've read 0.

I haven't been reading any Danielle Steele, John Grisham, Kathryn Stockett, or Stieg Larsson in the last 15 years either... but Grisham was much more common in my circle, and I read some, in the 90s. I had less fewer options! I read over 30 books last year, and none of them popped up in this article...