Unfortunately you are way more likely to get a blank stare when you say "add our RSS feed" than when you say "add us on Facebook" or similar, especially if you are an organization like a police department. Ordinary people do not tend to set up RSS readers or know how to handle feeds.

Picking a reader means making one or more choices (for your phone, laptop, tablet whatever), adding a feed is several steps, and it is easy to get overloaded with too many boring items (and too few interesting ones) because curation is left to the end user.

Centralized social networks require no choosing of readers, let you add an info source in one click, and ensure you have neither too few nor too many interesting items -- for some value of "interesting" -- regardless of how many entities you follow.

I love RSS and decentralization but creating a smooth, user friendly experience with such tools is a major unsolved challenge.