This piece was written by a highly-regarded scifi author a year and a half ago. I say that not to complain about the age but rather to marvel at the authors ability to describe so well something that is only becoming clear to many a year and half later.
I'm so mixed on that book. Lot of great info in it, some good thoughts on child development. But soooo much moral panic under the guise of science. The data used is fundamentally unable to establish a causal link.
Yes putting real life focus on children and relationships is a great thing for child development. So I guess a book furthering a moral panic to do so, while purporting to be above moral panic isn't fundamentally evil.
I'm worried it helps create a boogeyman, though, and the children it seeks to help are being harmed by the backdrop of the existential crises of our time like global warming, the authoritarian wave, etc, and social media / phones is just the most convenient vector through which this all flows.
Activity Pub is much more flexible, the tradeoff being that it's more complex. ActivityPub is basically a flexible CRUD API specifically designed for social networking, with support for federation.
You could fulfill the purpose of RSS with ActivityPub. But, it doesn't supercede RSS/atom, because the simplicity is valuable for the cases those protocols handle.
This seems more similar to word processors prior to PCs taking over that functionality.