I'm not disagreeing, but feel I should point out message boards require moderation and policies; same as any social media.
Meaning they can work when run by dedicated volunteers, but for-profit companies see them as cost-centers and eventually shut them down after they first cut moderation headcount and then let them turn into sewers.
(Forex, Crunchyroll.)
Lemmy is probably the closest Fediverse version of a message board. You might want to look at it.