Earlier quoted context omitted.
What's your baseline? While there are theoretically more secure alternatives to using a password managers, the vast majority of people don't have the discipline or skill to implement them effectively. Password managers make security tradeoffs, providing a nice balance of convenience and defense against many of the most important attack vectors. So while it of course possible to come up with basically endless possible…
The baseline is an encrypted libreoffice or txt file where passwords are stored. Then the file is somehow synchronized.
How is an encrypted odt/txt better?