Believing that either the Reddit exodus was negligible to that community, or that it was entirely decimated and left to Lenny are both inaccurate opinions. There was a very tangible effect on the selfhosted subreddit specifically when many left for Lemmy, and now both communities both feel like two halves of the same whole. Enough people moved over to lemmy that I truly don’t feel the need to open reddit hardly ever, but I do from time to time. I think lemmy also has a benefit that other fediverse sites like Mastodon don’t, in that Lemmy is not quite as allergic to the concept of discoverability, and the fact that Lemmy is inherently based around communities means that you don’t have to do the Mastodon thing where you spend the first month having to go out and follow a ton of individuals. You can just follow a couple communities and the content flows in.