> The root problem is that attention has gone from abundant to scarce
I don't think that's necessarily true.
I think the root problem is that running & using a forum is too difficult. That is why centralized forums (like you mentioned, reddit and facebook) that handle it for you won out against decentralized forums run by forum members.
Even before facebook/reddit/etc forums tended to live or die by individual effort of one passionate system admin dealing with all the hosting, updates, accounts, and spam until they get fed up and the forum closes because they can't find someone else to take the keys.
One of my favorite niche forums is https://archboston.com. It has years of deep-dive discussion from passionate users about the history and progress of Boston area infrastructure and real estate development projects.
For a while there the site was up but not allowing new accounts to be created -- someone was paying the hosting bills but didn't have time to do any admin tasks. Thankfully, someone else stepped up and people post new stuff every day (albeit with banner ads at the top of each page now, which is honestly not too bad)
I don't think that's necessarily true.
I think the root problem is that running & using a forum is too difficult. That is why centralized forums (like you mentioned, reddit and facebook) that handle it for you won out against decentralized forums run by forum members.
Even before facebook/reddit/etc forums tended to live or die by individual effort of one passionate system admin dealing with all the hosting, updates, accounts, and spam until they get fed up and the forum closes because they can't find someone else to take the keys.