Why is passwords of random words stronger than passwords of random characters?

If I understand correctly, than this video claims random words are stronger than passwords of random characters (the video does not claim does, but it cited sources). Isn’t it more susceptible to something like a dictionary attack or at the very least relatively easier to guess because there’s fewer words in a given length of password than there are number of characters?

Obviously from a user standpoint it’s easier to memorize only a few random words than a password of equal length full of random characters.

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