i use it to run my forums and it’s significantly better than any experience i’ve had with phpbb. i don’t know how much an activitypub plugin would be actually useful for it, given that that’s basically a niche for a niche, but if all you want is a community forum that gets delineated into different categories and has a fairly robust user-driven tagging system, you could do worse for replacing Lemmy imo
the biggest downside is that it’s not very friendly for low-engineering experience admins, especially if you want it to scale outside of a single computer it’s running on (separating the db from the web traffic, for instance)
it is simultaneously overrated yet exactly deserving of all the praise it gets
the way it encourages cooperation with a stranger is staggeringly rare in games and i wish there were more things like it