The demographics of who was online before the internet went mainstream matter a lot, here. It wasn't exactly a representative slice of the general population.
Forums were still going strong a decade after the Internet went mainstream. They only started to fade after smartphones took off and many forums took years to introduce mobile themes. For sports teams however, forums never faded, there tens of millions of users on team-specific soccer forums for example.
That's a good point. I think a lot of forums were less vulnerable for a number of reasons. They typically don't have a large audience (not all, but most), which makes them less of a target. They're also organized around niche interests that don't intersect much with politics and cultural issues, off-topic forums aside. And they're probably more heavily moderated than social media and blog comments.
I think the general point stands when considering large-scale platforms.
Were they global or local? I made that distinction intentionally.
Either or both, depending on the SYSOP's resources. I ran a BBS that did store-and-forward between the U.S. and Europe.
The ones with global connections could take a day to a week to forward messages, but that turned out to be a feature. We went outside in the real world instead of staying online arguing with strangers.
Usenet was US-centric but somewhat global and certainly not local. Even dialup BBS's were sometimes nationwide despite long distance phone charges. I wasn't into the BBS thing though.