Well actually, it sort of can.
Maybe not exactly as easy, but close to it.
Back when your vocabulary was limited to “mama” and “dada,” listening was how you learned new words and phrases.
Anything you overheard, your brain soaked up, and eventually you repeated it back.
The same method will work for you as an adult, because that’s how your brain is wired to learn a language. There are plenty of other benefits to learning a language through listening, too.