jointhefediverse.net seems to be a commonly linked resource for directing people to join the Fediverse.
Curiously, it does not list Lemmy under the list of Reddit alternatives. Their GitHub README explains why.
Previous relevant discussion: https://lemmy.ml/post/78808
I do, because I would like Lemmy to reach 100k monthly active users, so that other posters can join communities I keep alive. Lemmy.ml reputation is detrimental to this.
On the other hand, I respect the Lemmy devs as developers, just not as admins.