It’s another slice of Swiss cheese. If the user has a strong enough password or other authentication method through PAM, it might stop or hinder an attacker who might only have a compromised private key, for example. If multiple users have access to the same server and one of them is compromised, the account can be disabled without completely crippling the system.

Using sudo can also help you avoid mistakes (like accidentally rebooting a production server) by restricting which commands are available to the user.

If it is a war you want…

Clothes are always touching your skin. You can always see your nose. You are now swallowing manually. You can feel an insect crawling up your leg. And in case you have tinnitus, let me just say… eeeeeeeeeeeeee

Like manual breathing, or feeling your tongue always touching your mouth, I am now acutely aware of the position of my balls.