You don't need a blockchain for that, just cryptographic signatures and PKI. The EU is implementing a system for national IDs that would enable this, and could be done with perfect privacy through zero-knowledge proofs.
I predict that Worldcoin will get it done first, and will be more dependable than most countries. But it could turn out otherwise. In the end, services that need humanity verification will have multiple provider options and the market will decide.
Government solutions will be opt-out, and only in the most tedious way: Leaving the country, burning your passport and becoming a stateless person. Not recommended.
If there ever was a moat, government has it.