How should we revive our dead Slack community?

Hey everyone, looking for some real talk.

My co-founder and I have been grinding for three years on a niche community for women in HR. We started strong - hit our first 50 members just through our personal networks, and by the end of Year 1, we were sitting at around 120. FYI - we're running everything on Slack.

Fast forward to today: we’ve managed to scale to 400 members, but the engagement is absolute garbage. We’re lucky if we get two discussions a week. It feels like we’re screaming into the void.

The "bones" are good. We’ve produced a ton of high-quality, high-value content over the years that’s just sitting there. We’ve tried every engagement "hack" and strategy in the book to get people talking, but nothing sticks.

At this point, I’m exhausted. I’m seriously considering just sunsetting the whole thing, but it’s hard to walk away after three years of work.

Is there any hope for a community this quiet, or am I just beating a dead horse? Has anyone actually revived a "zombie" community, or is 400 members after 3 years a sign that the PMF (Product-Market Fit) just isn’t there?