When listening, we are reviewing a lot of English usage such as vocabulary, grammatical structures, intonation, accent and our own interpretation.
We can learn new words and expressions by hearing them frequently.
Besides the English revision, general knowledge from news, features, or even advertising spots is certainly beneficial for regular listeners.
We can imitate what we hear and apply it with great confidence.
Listening can be a good "hobby" while we do other things such as cooking, ironing, exercising, relaxing etc. In other words, we have no wasted time at all.
Listening is also a great way to train our attention.