What data reporting do you base that on?
From my own observations, and from comments on professional radio sites made by radio professionals who apparently have access to the data. Social media has been replacing forums and blogs and similar sites.
As for radio forums themselves, all one has to do is look around. I've seen some radio forums where there might be a posting once a month. You look through them and most of the postings were before 2015 or so. Same with some other forums that are not radio oriented. This thread started out talking about eHam. In 2012 or so when I joined it was a LOT busier.