Password-management apps are a great way to ensure that you create unique, strong passwords for every service, app, or site at which you need one, and you don’t have to memorize any of them.
However, what happens if you have a catastrophic failure, and can’t access your main computer? What if your backup drives are encrypted? (Yes, I recommend your backup drives are encrypted so that if stolen or accessed, they are protected.)
Or while you’re recovering your computer, you’re trying to access key financial, medical, or business resources, and you can’t access the password in the manager? Or your machine was stolen and you need a password to log into a tracking service, like Find My Mac?