It’s a solution, but very inconvenient. There is also no backup, in case of destruction.

It is also not encrypted. So anyone stealing it can read it.

A password manager is great for storing sensitive information like password in a secure way, at least if the master password is good enough. And the password manager isn’t a shitty one (Lastpass). The online password managers allow syncing, and also often can export a file.

Local password manager can also produce an encrypted backup file which can be stored on a server. While also offering some convenience to log in and storing many random passwords.