But those were for individual communication, I understood the parent comment to mean mass media ("useful for those in power"). I don't think the powerful feature of Facebook is the messenger, it's the ability to rapidly disperse information through sharing. IRC & similar communication tools weren't made for that.

WhatsApp is a hybrid, I suppose, but even there I think the share/forward feature is what drives the political usefulness, which is also why they're limiting that for some media, so you can't spread messages as easily (if it has been forwarded five times, you can only forward it individually, not to multiple contacts/chats, from what I understand).