I’ve mostly been to forums that favor the latter format so that’s what I’m used to (and why I made a group for it that is looking for participants, it’s like making more flexible communities within communities, a federation inception), but I was wondering where you would draw the line.
If the topic is repeated a lot, or there’s an ongoing event or incident happening a megathread seems helpful. All the important information and recent developments can be pinned to a single post, instead of having to trawl through each discussion to either help others find information or to get more info yourself.
Communities that are huge might deploy these more often for lower scale events, as I can imagine the umpteenth thread about some change in a video game being stupid can cause the rest of the community to start disengaging, which is something you want to collectively avoid.