Fediverse memes

This is the real answer. I forget the exact numbers, but the vast majority of people on reddit are just lurkers. When you have an enormous user base, that still translates to lots of content to consume. Lemmy has way less content and very small communities (if any) for most niches.

Of course you can point to bots on reddit inflating those numbers and that Lemmy has more meaningful interaction, but that's not what most are looking for that are on reddit.

Also, as others mentioned, there's no negative engagement algorithm drivers on mastodon like there is on Twitter. Fact is, a lot of people just like to be angry and combative.

Voyager, Thunder and Arctic blow the Reddit app out of the water

This is not entirely true, at least as phrased here.

1. Our quality of discussions is way higher, in our opinions, even though yes their topic range is so much more narrow (Star Trek, Linux, various Fediverse aspects, etc.).
2. There are no ads, for some that is VERY noteworthy, especially those less technically inclined.
3. As others mentioned the apps here blow the official Reddit one out of the water.
4. (Edit: there is much more, I did not intend this listing to necessarily be comprehensive, e.g. one that I see people mentioning is a focus on user privacy.)

So all of this is not "nothing", even though yes it is also not "everything" either.