nothing's stopping your local city council, library, or fire department from shoe-horning the ActivityPub protocol into their existing website (like WordPress or Drupal or whatever CMS they use) and immediately turning their site into their own Twitter service.
I'd like to see RSS come back in a big way, but replace RSS with ActivityPub and instead of nationalizing shitty centralized commercial services, adopt the protocols that allow for distributed and federated social activities.