it's way more active than people think it is. it's just a bit of a closed garden app that is mainly text-based, so posts only get shared onto other sites via screenshots, and people always assume that those screenshots are ancient relics from like 2008 but really most of the time they're from like a couple of months ago
as a side note, the CEO said that they're going to implement activitypub into tumblr so hopefully in the future they'll be an integration between tumblr and the fediverse, which would be cool
I've just rechecked and it's now fallen off front page - it was this: https://old.reddit.com/r/nottheonion/comments/14coqxp/reddit_is_in_crisis_as_prominent_moderators/
It was "23 hours old" when I posted that comment earlier, it's now "1 day old", so I assume it dropped down in the rankings because of that. But it was on the front page when this post was made