Two extra advantages of vault based password managers:

1. The manager can automatically change old passwords for you. LastPass support a big set of websites, when Dropbox was hacked this was very handy. I like to change social media passwords every few months and this makes it very easy.

2. You can store passwords that you can remember if necessary. Sometimes I need to access a password for a service or a site in an environment where I don't have an easy access to my password manager, for example when I'm using a friend's phone or when I SSHd into another machine. In those cases is handy to have some passwords that you remember, but are stored in the vault just in case you forget them. I only do this for a few passwords, but it's a nice feature to have.