> I don't understand how this solves the issue in this case.

I'd say since it is a local only tool, you don't really need to update it constantly provided you are a sane person that don't use a browser extension. It makes it easier to audit and yourself less at risk of having your tool compromised.

It doesn't have to be keypass though, it can be any local password management tool like pass[1] or its guis or simply a local encrypted file.

[1] https://www.passwordstore.org/