Earlier quoted context omitted.
Blockchain has value here, essentially acting as a distributed collection of digital signatures. If I need to prove my date of birth, why not present a credential, signed by the vital records agency of where I was born to prove it without any data broker in the middle?
Signatures exist outside of the blockchain. You can just send your signed data point, that's the point. The only thing the blockchain protects against in these circumstances would be that the government is denying ever signing your date of birth and you losing your signed token. I don't think that's a problem in practice in most countries where an alternative trust system would even work.
That approach doesn’t scale.
It’s easy to shit on blockchain, but this particular area is one worth understanding.