What bothers me about Discord and other small groups like that are how they're difficult or impossible to search for
That's always been the biggest problem with Discord, Slack, Teams, and any other chatroom based communication tool. They're good for realtime or near-realtime communication, but using them as a reference library is a kludge. Searching through multiple Nerf related Discord servers for information is not usually very quick of enlightening.
Reddit and Forums are not a panacea for searchability, but they can work a fair deal better for documenting hobby stuff. Discord and Reddit have the same problem of being proprietary platforms that are experiencing a lot of pressure to monetize, and lock away all this information. They ultimately don't care about the health of a subculture of fans and hobbyists.
The history of Nerfhaven does demonstrate some of the limitations of trying to run our own fansite. It's completely dependent on the goodwill and effort of a few people to keep it running, and is vulnerable to the forces of entropy that act against internet-facing services. A major example being: new user registrations being turned off for several years now, because of the relentless and overwhelming onslaught of spam accounts. And so the decision was made to basically just put NH into hibernation... but to preserve it as a library of it's era of Nerf hobby stuff. In that way, I think it has already proved itself more useful and durable than a lot of other Nerf social media, which is slowly disappearing from history.
I'm hopeful that in the next few years someone will come up with a better social media solution for hobbyists, something that includes the real-time communication for Discord, the ability to post articles, the ability to have threaded conversations, media hosting, and for all that to be searchable and preservable.