Part of the reason is Lemmy's default sorting algorithm for comments, "Hot", addresses reddit's biggest flaw, which is that earlier comments snowballs with upvotes, so it buries late-comers to conversations, leading to the rat-race of everyone trying to get their funny one-liners in as early as possible for maximum karma (which also isn't a thing here.)
The "Active" default sort for posts also means that comments are a lot more concentrated to what people are actually talking about and posts tend to be stickier. (also, botting upvote is a lot harder on Lemmy, since it's easy to bot upvotes, it's a lot harder to fake real conversations in comments. )
In fact, it is pointless to comment at all past like 4 hours on any post on reddit since it will just sit unread for hours, but here you can comment 1 day after a post and still have people talking to you.