A plain text physical password notebook is actually more secure than most people think. It's also boomer-compatible. My folks understand that things like their social security cards need to be kept secure and out of public view. The same can be applied to a physical password notebook. I also think a notebook can be superior to the other ways of generating and storing passwords, at least in some cases.
use the same password for everything: obviously insecure.
Use complex unique passwords for everything: You'll never remember them. If complex passwords are imposed as a technical control, even worse if you have to change them often, you'll just end up with passwords on post-its.
use a password manager: You're putting all your eggs in one basket. If the manager gets breached there goes everything.