I don't necessarily thing it has to be too big, it could be spread out into tiers.
Big doesn't necessarily mean good. Look at all the 'big' b!tcoin influencer accounts. They bring no one of any interest.
So yeah obviously not b!tcoin bubble, for starters.
People who would genuinely want to use nostr (if there was an audience here), people who are interested in the principles of it, people who don't talk about b!tcoin but are interested in it.
(These are not necessarily endorsements if them entirely).
But some examples that tick a lot of these boxes:
Jay Dyer springs to mind.
Sam Hyde.
Chycho.
Sort of a bit of a range there of reach, but an actually interested and engaged audience follow them.