Of course posts older than a day are still useful. But how useful is an experience report on an OS that is over 2 years old? I have no idea about Void Linux, but whenever I seek a tutorial on something, I limit the search to 1 year, because stuff changes. Take the discussions on VPNs recently for example. For many people a lot changed due to policy changes from some VPNs. All threads regarding those VPNs that are older than 3 months should be viewed as archived.
One could argue that a post from programming humor is still as funny as it was 2 years ago. But I don't want to see the same post over and over again, just because someone wrote a comment in it. And old posts aren't gone and can be found if one wants to. But I don't want posts to stay on my front page for years.
This makes lemmy almost not usable for me. If I sort posts by active or hot, I get 80% posts that are older than 2 years. Always with new comments.
I belive that fixing the sorting algorithms is extremely important for lemmys success.