It was really hard to make truly private properties that couldn&#x27;t be leaked in some way without WeakMap. If you don&#x27;t need foolproof leakage, Symbols are a more convenient way to get most of the benefits of private properties. This is intentional: as I recall, the committee realized that WeakMap wasn&#x27;t the most ergonomic solution and created Symbols as a more convenient, though less ironclad, alternative.