No idea about Pixelfed, which I don't use. I thought the article gave an interesting perspective on the internet in general, not just the fediverse. So the concrete stuff about Pixelfed, cross-fedi accounts, etc. didn't seem that important.

There are some interesting posters on Mastodon and also on Lemmy, but I think the fediverse in general is nowhere near what Usenet or Reddit used to be. No idea about Facebook or IG, both of which I stay away from, though there is a musician on IG who I was thinking of emailing to suggest cross-posting on Youtube.