This is a good question. I spent a decade on various motorcycle and motorsports message boards and was shocked when I visited one of my old haunts recently. In its heyday we were getting over a hundred posts a day across the various subforums. I fell out because I sold my bike and started to pursue other interests, seems like many others did the same.

The other thing that happened across a lot of motorsports forums and websites was that a company called Verticalscope bought out the founders and started putting ads everywhere. It made the site slow to load and difficult to use. Worse still was seeing our founder cash out. We had moderators, authors and all sorts of people contributing to the community and while we all knew the founder, none of us ever really thought about ownership and profits - I think we all just figured it was a hobby for him like it was us. At any rate, as a community we generated a lot of material and a lot value and then he took that an ran. OK, lesson learned but from that point on, I and other authors and moderators stopped contributing our material. I eventually went to a website where, as an author, I was paid for my articles - paid, oddly enough, by verticalscope...

I think some subreddit have replaced a lot of what was going on in forums but they have limitations. The subreddits that are small enough to have communities usually don't generate enough posts to keep me interested and the ones that have all sorts of members have no community. When it comes to something like riding a motorcycle experience counts, but in a big subreddit you have hundreds of people speaking and you know nothing about any of them. And brigading on those forums is real - I see bad advice get hundreds of upvotes while good advice goes nowhere. It's OK for me because I can tell the good advice from the bad, but for a new rider looking for real advice it is likely to get someone hurt. Better if we were back in the forum days where, on our forum at least, if people wanted to give advice to new riders we asked them to post a rider's resume so people had some background.