Instead of writing software, one can just combine local crypted or non-crypted information with information stored on distinct devices, including own brain or cell phone. This prevents accessing the full information for intruders of the computer account. With such practices
a password manager doesn't really need to be written.
Say one could use a plain text file, or perhaps use a password manager
to fool an intruder, but each password would be stored only in part,
or in an altered form. Algorithms, or added information from one or
several separate sources would provide the missing information.
In any case methods for storing static passwords do not help against