Also, there are free organizations, the only limitation is that they are two people only and only two collections (vaults).
But honestly, I do not see how your request is any different from what is available, free is two people and two collections, family is six people and unlimited collections, and enterprise/team is a per person cost with unlimited collections. Each collection then has unique permissions per user (your idea of personalized vaults). Please correct me if I am wrong but that is how I see it.
Also if all of your collections are part of a single organization, i.e. not multiple free organizations, you can even view all passwords since collections are effectively folders but for the organization.
Check this documentation out and see if it provides what you are asking for:
Get Started with Organizations | Bitwarden Help & Support