If someone like Joe Rogan joined nostr it would be seen as a monumental win, however the behavior of users would immediately start to shift from creating to consuming.
While you are not obligated to follow celebrities, their presence and content has a ripple effect, causing the whole platform to become performative. The result is most users just take a back seat and become passive consumers.
Twitter would not have survived without the arrival of the celebrities, yet we saw how that turned out in the long run.