A lot of forum veterans (whatever that forum may be) tend to remain on their preferred forum regardless of new forums popping up. So that would go a long way to explain more traffic over there (despite the downtime). I've also had people tell me privately (sometimes because I would ask) why they preferred the other place over this place, and they seemed to say there were more lengthy posts of a highly technical nature over there. But honestly, anyone could do the same here. It's just a matter of will, actually.
As one of the first flight of added moderators over there in the far distant past, I've seen several forums pop up due to limitations there and then die on the vine. For whatever its shortcomings, it has been around for 24 some years and likely pops up first in searches when new folks are looking for help/community.
Full disclosure: I'm biased. I played a small role in making this forum happen, alongside a band of some insanely great people. I cannot help but feel this forum is pretty awesome. Members have the freedom to Like posts with cute little Mac icons . . .
Therin lies the rub, those cute little Mac icons are exceedingly frustrating comment/discussion killers. Lack of activity on the forums here would likely be why most development work happens over there. A "like" pales in comparison to posts by folks interested in and wanting to make contributions to a development or hacks topic.
Swinging back to my first comment, lack of such activity here is a major limitation in terms of folks finding us. Having been active there on many fronts for so very long, I receive a lot of requests for help in PM and have done so, encouraging them to open up a topic to get help from the gang. Since winding up here, I've recommended this place several times in PM over there and been told folks lurk, but have no interest in joining up.
Reaction "posts" just suck in comparison to a few words of encouragement or interest in even short post here. If editing were flexible there, I'd likely not post projects here where I can correct grammar, fix mistakes or flag as edits further clarification or to substitute the perfect word remembered after the edit window lapsed and an almost, but not really good enough word is recalled.*****
IMO of course
***** that'd be my Disnomia/Anomia limitation at work.