This is the first article in a series that will be a fairly critical review of ActivityPub from a trust & safety perspective. Stay tuned for more.
In the modern day, myself and many other developers working on libre software have been exposed to a protocol design philosophy that emphasizes safety and correctness.

See also https://overengineer.dev/blog/2019/01/13/activitypub-final-thoughts-one-year-later.html