That's like asking if Bitoin could grow to your fiat currency of choice size.

Nostr isn't a social network, but a protocol with the potential to become much larger and relevant than any social network ever has o could. So, that's not a fair comparison, for fElon's site, that is.

Maybe one (or more than one) of the nostr clients could grow to it's size, another one to Pinterest or IG sizes, another one to µ€ŧ@ size... but that would not be Nostr, but a tiny part of it.