At a high level it lets you separate (and centralize) your PII data from your main infrastructure whilst providing configurable semantics on how the data should

At a high level it lets you separate (and centralize) your PII data from your main infrastructure whilst providing configurable semantics on how the data should be encrypted underneath. Additionally you'd have granular control (and audit) on who/where/when (access control, geo, time) can access the vault. As an example you'd ship Social Security Numbers to the vault and configure access to it for a KYC application which can verify the SSNs as needed.