> Video is only limited by our capacity to produce enough of it at a decent quality, otherwise humanity is definitely not looking back fondly at BBSes and internet forums
Video is limited by playback speed. It is a time-dependent format. Efforts can be made to enable video to be viewable at a range of speeds, but they are always somewhat constrained. Controlling video playback to slow down and rewatch certain parts is just not as nice as dealing with the same thing in text (or static images), where it’s much easier to linger and closely inspect parts that you care more about or are struggling to understand. Likewise, it’s easier to skim text than video.
This is why many people prefer transcripts, or articles, or books over videos.
I seriously doubt that people would want to switch text-based forums to video if only video were easier to make. People enjoy writing for the way it inspires a different kind of communication and thought. People like text so much that they write in journals that nobody will ever see, just because it helps them organize their thoughts.