Indeed, a lot of people are spending more time on social media rather than on forums. That's why many forums disappeared entirely in the last couple of years and continue to do so at an alarming rate.
In my opinion, communities that can offer what social media doesn't will be able to thrive. As social media is mostly into fast content, forums should encourage debate, develop quality, well-researched content, and, most importantly, be niched. So they will be able to gather specialists and beginners together.