The problem is that LW is not getting many impressive posts from either talented outsiders or regular commenters who managed to graduate into quality article writers.

I suspect EY making Roko flame out in 2010 set up a dynamic where fluff posts and snarky comments are fine, but being an outsider who can write quality posts about something actually interesting is not, since that sets you up for a similar loss of face. People who could write the sort of content LW was supposed to be getting can do so just as well at their own blog which isn't subject to random bursts of MIRI autocracy, and most seem to do that.

Also, LW doesn't really have an incentive structure to go above and beyond writing stuff that the average reader will upvote after a quick read. There isn't a ladder for local posters who are hooked to the local feedback systems to go up into producing increasingly impressive content from the status of "frequent commenter who receives mostly upvotes".