With the vast majority of Lemmy users being refuges from Reddit, it's easy to see why "Reddit ded" circlejerk is strong. It's the most relatable thing to everyone here, as nearly everyone here can relate. Not to mention it's the only thing that unites us as it is the only thing we have in common, regardless of which community you used to belong to on Reddit.
But, I do see those posts less and less. As time went by, I'm sure people will move on from the circlejerk (probably to another circlejerk, but at least they do move on).
When it comes to the lack of content, that's due to the lower number of users. It's hard to say if whether it'll get better as it depends on which kinds of content you are looking for.
But if you want more content, try sorting by new. Reddit death content will usually get more upvotes as it relates to more people than any other content, but the "new" sorting should eliminate this bias.