I think it's the evolution of information, when i first had a computer my messaging was on fidonet, my messages were compiled and i'd upload them to a hub and that guy would compile all the other peoples message and upload them further. Next day later i'd download my messages and maybe get some answers. This was over modem, really slow but it worked. Then came CompuServe but i joined AOL which was a complete dial in service. it had groups, messaging, chat and other stuff but was expensive. move on a few years, faster connections, better software and forums. Today it's social media, information on tap, available on your pc, smart device, phone at the touch of the screen. You want info on a new pit, a search will find something. I don't think forums will disappear, i think they'll contract and lot of the more esoteric or frivolous ones will go but the 'grass roots' types will survive and remain relevant. I'm getting to be a dinosaur, i prefer a powerful pc on my desk with a large monitor, i have a smart phone but probably use about 20% of it capability. I know teens that don't own a pc or tablet, just a phone and they do everything on that. plus i'm sure they don't know a phone is held to the ear not in front of the face and spoken into on speaker :-)
Information delivery is constantly evolving.