This assumes that the period when Eliezer was writing a lot was pretty optimal, and we should be trying to recapitulate that era of success.

The OP states that, and I think I agree, in the sense that if there's a topic that would be as general and as interesting as the Sequences, then I would rather someone write a long text about it here than them not do that. I suspect, as I've argued elsewhere, that there isn't something in that class; there are lots of interesting things for people to do now, but they aren't going to be as common an interest.

I do think that there are changes LW could make to adapt to the new community and purpose for it, but I'm not sure here is the best place to discuss that.