Yup. Too many forums, and changing tastes too.
As example, two of my second cousins who are a generation younger than I, are somewhat active on FaceBook. I'm not 100% sure how they spend their time online, but I'm under the impression they aren't spending time on forums such as these.
While I agree that platforms like FaceBook have their merit, I also don't really care what my FaceBook 'Friends' have for breakfast every morning. Nor would I necessarily want even half the stuff I post online associated with my real name, especially in this day and age when people get offended if you even look at them wrong. Won't even get into the issue of what they do with your personal info... Perhaps the younger generations are less concerned about it.
But ya, forums like this will eventually go the way of the old Bulletin Board Systems... Essentially extinct now, but a few still up and running for the purpose of 'nostalgia'!