There are multiple mental maneuvers that one can take in order to come to very different conclusions about what /jp/ is now compared to the past, and whether or not it's better for it. What it is today is an island of stability that people in fact wished desperately for some years back. Is the board more memorable and meaningful for it, though?

I would say that some of what may be wished for / desired in this conversation is confined to the past. What is desired? A pleasant, very relaxed and open (but vastly storied and experienced) atmosphere, and authentic excitement for the place itself? Such trends may be more of related to when the board still very much felt like an /a/ offshoot in 2008, a time quite different overall from today for not just /jp/ but also /a/ and 4chan as a whole. Subjects that had intermingled on /a/ now had their own place and with that came a prevailing wind of users and common bonds. The wind died down over time, and with it the common bond of the board.

What we see on /jp/ today with a balkanization into preferred enclaves is now endemic to many boards with lower posting rates 4chan-wide. The longer time it's been away from /a/ with more cycles of user turnover, the more it's diverged. Old /jp/ is to me like an exotic, long-extinct fantastic creature of history, like the anomalocarid Aegirocassis benmoulai - heavily derived from its former niche, making a success for itself very different from its contemporaries, utterly spectacular. I look at Touhou threads on current /jp/ but don't see the progeny of Aegirocassis. Rather, I see in each a Schinderhannes bartelsi - same lineage of creature, but swimming around in a far-future world that has evolved much around it, its very existence a shock from having existed past several extinction events. It's evolved new features for its lineage, but will never turn back into that Aegirocassis even if you protected them in a private ocean. You'd AT BEST get something convergent, but never the same.