Lemmy is mostly a clone of reddit with a lot less people on it. That is to say it works fairly well and doesn't yet seem filled with bots, but its got the same issues as Reddit since its based on the same design.
It degrades the "does this post fit the subreddit's theme/topic?"-signal and makes the average user work against the moderation team rather than supporting them.
This was exacerbated when they started showing posts from subreddits that the user is not even subscribed to on the front page rather than just ranking posts of subscribed subreddits.
It was a good idea, but it seems to have withered.