lemmy.world has 3 times the amount of users as lemmy.ml. Also lemmy.ml has an application process for becoming a registered user, so there definitely is some kind of bias as to who is registered there.
You are talking about instance and OP said he's used the biggest(actually 3rd) community which does not require its users to be from lemmy.ml So I don't see your point
You do know the difference between communities and instances, right? And you do know how federation works, right? Also, based on where you look, !asklemmy@lemmy.ml is either the largest or one of the three largest communities on lemmy, so I don't think there's much bias in there