This is often called a "stateless" or "generative" password manager, and while they do have some benefits they tend to be rather niche.
The main issue is losing the ability to easily change the master passwords as well as making it more difficult to deal with password requirements.
Also, for most users the sort of access needed to steal an encrypted password vault isn't much different from what is needed to grab a master password as its being used, so the benefit is very limited.
This is often called a "stateless" or "generative" password manager, and while they do have some benefits they tend to be rather niche.
The main issue is losing the ability to easily change the master passwords as well as making it more difficult to deal with password requirements.
Also, for most users the sort of access needed to steal an encrypted password vault isn't much different from what is needed to grab a master password as its being used, so the benefit is very limited.