I think they can be much more secure than:

• remembering your ( probably weak ) passwords

• writing passwords on paper, which is slow, you can lose paper, break it, or someone can steal it

• storing passwords in unencrypted text file

• reusing passwords/password!

I use KeepassXC, which is offline, encrypted password manager. Every password is stored in one file, which to access, I must enter the one password I do remember. I recommend having backups of this file.

It has password generator included, so all my password are long, strong and unique. It also can auto fill password/login which saves time.

To increase security of your account even further you should also use multiple factor authentication, for example app which generates one time codes on your phone offline. It will protect you, even if your password gets leaked, or cracked.