I would argue that forums are somewhere on the continuum and the “direct predecessor” of social media if that makes sense. You already see in which topics something happened which isn’t too different from following a Facebook page.

On your last point, I disagree. Time is relative. There is a difference between free time you can actively plan and idle time between meetings where your boss could bump in any time. At the end of the day looking back, you might have had enough time to write an article, but there could always be a call coming in so you end up using that time looking at cat photos and arguing with strangers about football.

This might depend on the kind of BS job though. Graeber described a wide variety and for some, your argument works but not for all.