People who use lemmy are more likely to be power users. The people who use their reddit account once a month generally don't know or care about the issues that caused a lot of us to migrate.
I think the users on here tend to be active on the site in general rather than just a few specific subreddits. And also the small amount of users all interacting on the same communities gives the entire site the feeling that smaller subreddits used to have. Which was always infinitely better than big subreddits will millions of users, infested with bots.