… advertisement and push they did on sites like reddit…
The lemmy world admins advertised on Reddit? Can you link an example?
… their listing on join-lemmy.org…
Until recently EVERY lemmy instance was listed on join-lemmy.
And with the name Lemmy.world they did nothing to dissuade anyone from thinking that.
They run a family of servers under the world tld, including at least mastodon, lemmy, and calckey. They’re all named similarly.
I also saw nothing from .world not claiming to be the bigger instance(super lemmy)
They ARE the biggest instance, but that happened organically. It’s not based on any marketing claims from the admin team about being a flagship/super/mega/whatever instance. People just joined, and the admins didn’t stop them (nor should they). It’s not a conspiracy to take over lemmy. It’s just an instance that… until recently… happened to work pretty well when some were struggling.
The Beehaw admins made this choice, and documented their rationale here: https://beehaw.org/post/567170