Passbook accounts are a specific kind of account known for having both lowered requirements (balances, credit of the account holder etc) and for subsequently lowered rates. They are for children and old people.
I admit to glossing over your use of the term but now that you’ve pointed it out it’s an even more egregious use of the wrong tool.
Fair enough, savings accounts are an anachronisticity bordering on a scam. The proper products are money markets or Treasuries being bought into a brokerage account.
"Passbook" is the traditional term for these accounts.