Yeah, I've had very similar thoughts! Though the angle I tend to take is that social media is driving the Internet to hell in a handbasket
(And the scary thing is that it isn't even by design
, in the sense that nobody set out to make Facebook or Twitter what they are at the moment -- it's all unintended consequences and self-reinforcing metrics.)
There indeed used to be this feeling that the 'net was bringing people together, precisely because you would run into folks wildly different from yourself in places like, well, this
, and people would discuss a wide variety of things. I've done some diving here, and this place was pretty amazing in it's heyday, nebulously around 2008-2010 or so. Certainly better than any forum I was ever part of.
I think the magic ingredients are good moderation and, not unrelatedly, community size. Both because the effort required to moderate scales with the number of people (and probably faster than the number of people) and because past a certain point, I think the whole idea of a 'community' breaks down and you end up with a sea of strangers. Contrast living in a small town with living in a big city.