It honestly seems like pubkey is just regressed nostr from what I can tell.

I don't have an invite link, but so far the only difference between nostr and what pubkey is claiming to be is that you have to be 18 to use pubkey.

Which makes me wonder is pubkey just a bunch of porn and gambling?

Someone mentioned you can't send zaps on pubkey either, can't confirm as no invite.

I don't think nostr is perfect, but from what I can tell pubkey may be a step backwards from nostr.