On the off-chance that you are not asking this in bad faith…
All speculators go through a KYC with their exchange, which identifies them very precisely.
All other users paste it publicly, saying “I own this account! Send me money.” And even those users often have to convert it back to fiat, which requires an exchange, which makes them go through a KYC.
Ah, right, Bitcoin exchanges in USA, and elsewhere, harbour personal identifiable information. Bitcoin doesn't impose it, but it's a practical requirement in some jurisdictions.
All speculators go through a KYC with their exchange, which identifies them very precisely.
All other users paste it publicly, saying “I own this account! Send me money.” And even those users often have to convert it back to fiat, which requires an exchange, which makes them go through a KYC.