Think it's been summed up by the other comments. The site is kinda niche, it's one of many collection tracking sites. A lot of these are just apps now. Most of us discovered this place around the same time, and at about the same phase in our collecting. A lot of us participated in the discussion as a group that was still learning, exploring, and trading notes on the state of collecting then and continued to do so until we were near just repeating ourselves. Now, it's a much different beast and much more difficult to be into this hobby, many in our group becoming jaded and apathetic towards collecting over time. We achieved a lot of the basic goals we sat out to achieve, all those years ago. If the state of collecting itself becomes stale to the group, then the forum will fall off. The site did not attract the attention of younger clusters of game collectors. Instead, many moved on to more visible and accessible platforms for such discussion like Reddit, Facebook, etc.
For the record, I'm still about as active as ever in game collecting; and instead of looking for an out, I'm looking towards reasons to keep my interest and finding more all the time. I usually don't post about my escapades or my pickups a lot here anymore, mostly because as you mention there's very little engagement and I feel like there's an apathy towards topics which interest me, or posts I make. For me it's more satisfying when I can connect with groups or individuals that are more on the same wave-length as myself, and I don't sense that here much anymore like I did in the early 2010s.
