I have. Lemmy is especially good for content geared towards news, tech, FOSS, privacy, memes (if, unlike me, Reddit-style memes are your thing), et cetera. For me, that checks off all the boxes for what i used Reddit for, so when i started using Lemmy, there wasn't really anything i was missing from Reddit. So, while i'm willing to miss out on some content in order to drop Reddit, i haven't really needed to.

However, this definitely isn't the case for most people. If people are just using Reddit for certain things they just don't see on Lemmy, that's totally fine (though i hope they're using an ad blocker or something), especially if they stick around for when Lemmy does start having that kind of content.

Growth isn't a straight line and there will be points of fluctuation, stagnation, and decline.