"The growth" of the fediverse in general or of any platform in it is not responsibility of one server. The only thing Beehaw admins are responsible for is Beehaw.
If you want Lemmy to grow create your own communities and threads, participate in other people's communities and posts, etc.
there are more than 1000 Lemmy servers, many of whom are open to community creation (something that Beehaw never has been)
Go create content on Lemmy if you want it to grow.
BTW, "growth" is not necessarily a good thing on the fediverse. Growing too much can be the death of a server.