I imagine that in the future we will have less trust in strangers on the Internet and whether they're human or AI will be a side issue. Knowing that a correspondent is human will be neither necessary nor sufficient.
One alternative is https://self.xyz . It generates ZK proofs from the digital signature on your e-passport or national ID card. That allows you to prove "human" or "over 18" or "not on the OFAC list" without revealing your name, date of birth or nationality.