Boost was my favourite Reddit app, couldn’t tell you why off the top of my head because I’ve been using it for so long now
Think a lot of people are excited because it’s the same app they’re used to which was pretty damn good as far as Reddit apps went
Also I think for a lot of people it’s closure to the whole leaving Reddit thing, at the moment I think the experience is more or less equivalent to what Reddit was but the interface can still be unfamiliar and janky sometimes. Makes Lemmy a drop in replacement for old Reddit users