I saw some engagement graphs a few weeks ago for a few niche subreddits. Not necessarily niche in the "small" way, but in the "focused interest" way.
Posts and comments per day completely collapsed during the 3rd party app-pocolypse, and never recovered. Community membership didn't even show a blip, but actual discussions fell off a cliff.
The Reddit app is really bad, and the website is worse. The mobile website is somehow the worst of the lot. Doing anything but voting and scrolling is painful. Reddit has successfully ended its usefulness as a community space. Most people there don't aeem to have noticed this sea change, yet.
Or at least, they've found no compelling reason to go elsewhere yet.