that is not how blockchain or banks or government work! none of them have anything to do with "passwords and personal information"! banks hold and control your money, and governments snoops around in your personal affairs. and blockchain is just a public ledger that holds transaction history protected by cryptography. it is not supposed to hold your passwords or personal information.
.. that is not how bitcoin and financial instituations works you mean.
blockchains DO NOT have to be limited to 'transaction history'
a blockchain could easily hold a publickey and a social scurity number
1P0oy487Addr355 : SS xxxxxxxx
then when signing into any service, you dont need stord 'passwords' on institutions. you simply need to sign a message using ur key
EG imagine your with bank of america, and you have your bank account linked to ur social security number
bank of america log-in screen
"please paste signed message of: B0A ssxxxxxxxx May42019 rand:6852455"
now by pasting in a signed message. you have not revealed the private key (your control) but you have proved your identity to log into your account