Nowadays, most people use password managers (hopefully). However, there are still some passwords that you need to memorize, like master password (for a password manager), phone lock, wifi password, etc.
Security wise, can passphrase reach the strength of a good password without getting so long that it defeats the purpose of even using it?
In the linked comic, Munroe assumes an attacker knows your method. The attacker isn’t brute forcing character-by-character, but word-by-word, with an attacker who already knows you’re using 4 random words.