I'm lucky enough that my main hobby's primary discussion era is an old-school phpBB, and it's likely not going to migrate to Reddit or Facebook or somewhere else. It's great. Content is fully indexed by search engines and can be easily searched using those engines. Decades of FUD from cloud providers and centralized services have convinced so many that hosting your own server is difficult and expensive and scary and just not something normal people do. Online communities really need to get back to self-sufficiency.