You can have a very secure facility that only uses a "house key"-style entry flow for the user. The key will look really weird (see Medeco and Evva for examples

You can have a very secure facility that only uses a "house key"-style entry flow for the user. The key will look really weird (see Medeco and Evva for examples) and the building will have some design compromises - few entry points, no openable windows, etc. A password, in theory, could work the same way. Except that the normal password UX involves people remembering the password, which entails a huge security compromise.