And could they even still communicate effectively? Except landline and snail mail, what kind of possibilities are there left to exchange / propagate messages?

And could they even still communicate effectively? Except landline and snail mail, what kind of possibilities are there left to exchange / propagate messages? Pagers are (more or less) dead. Telegrams are dead. Fax is (more or less) dead. Newspapers are dying. Amateur Radio, Flyers and public squares would still work, though.