As a personal observation, seeing it in this article was the first time I heard that they also had an AMA on Reddit in parallel, and I was positively surprised to see, that Lemmy had the vastly better numbers here, (and, subjectively speaking, more insightful questions, too).

Lemmy - 1035 upvotes, 7 Downvotes, 226 comments

Reddit - 251 score, 71 comments

Of course that is the most favourable demographic to expect to perform better in the Fediverse - FLOSS fedi enthusiasts - but still, it shows the giant userbase alone does not have to translate to better engagement for your topics on Reddit. First time I saw that live in action.