If you build a community of value, people will take the time to create topic names. I look at it as quality over quantity… but it depends on the community too.
I think you need to decide what kind of engagement and community you want to build then pick a platform based on that.
Whatever you build it needs to offer something that social media and the other forums do not.
There’s tons of reasons why various forums have died, very seldom are they platform related. Don’t read too much into the demise of the other forums beyond understanding that whatever you build needs to have a reason to exist.