I believe what you’re experiencing is just part of the growing pains of Lemmy. I’m here from reddit as well, and something to keep in mind is this: According to the-federation.info, on May 1st of this year, there were 2,750 active users on Lemmy. Today, there are 85,045 active users, an increase of ~31x. The sorting algorithms for content on Lemmy are meant to handle a few dozen posts a day, not thousands. This causes things like Hot to show four year old posts just a few pages in, or the same article to be posted to the many duplicate communities that are springing up as Lemmy explodes in size. Over time, centralization will happen to a degree (it’s already happening with lemmy.world vastly outstripping lemmy.ml as the largest instance), which will consolidate the horde of communities into only a few, like how subreddits that offered the same type of content eventually consolidate into one or two.

Is there really a meaningful difference between /r/damnthatsinteresting and /r/interestingasfuck (prior to the protests)? Not really, but then there’s also /r/interesting, /r/mildlyinteresting, /r/moldlyinteresting, /r/interestingaf, /r/interestinggifs, /r/utterlyinteresting, /r/interestingbutcreepy, /r/reallyinteresting… I think you see the point. Right now, you’re subscribed to ALL of those, and people are aggressively trying to grow each one, which means they see a LOT of duplicate content. As Lemmy stabilizes, a lot of them will wither and essentially die off. It just takes time. The tough part is not knowing which communities will become THE community for a topic, so subscribing to all of them for now makes sure you won’t miss it.

It’s mainly because you’re on lemmy.ml. They defederated lemmynsfw and pornlemmy, which are the biggest nsfw instance and a fast-growing nsfw instance respectively. You need to join another instance that is fine with nsfw federation to see it.