Interesting video, makes a lot of sense. Just a couple of things to add:
In the old days of forums it's worth remembering that people on the internet had more in common with each other than they do today - i.e. generally they were people who were in to computers.
What really gets me down these days is the extremely low-effort of posting everywhere you go. I think that partly comes from the impersonal nature of online communication. Nobody knows who anyone is any more.
I agree it would be better to go back to independent message boards but it's a shame there's no "call to action" - it would be nice but how do we get people to do it? This is a popular YouTube channel, it would be great if it started some kind of ball rolling.