Like scales, arpeggios are a very important skill for piano players to master. I always had them in my mind as another technical skill and not entirely useful for the types of music I wanted to play. Just another item on the list of techniques to be practiced each day.
But arpeggios are SO useful! First of all, they will help you to master those chords because they are basically chords that have gone for a jog! They will also help you to develop dexterity, hand independence, and get really comfortable with moving up and down the keys.
The new way to learn piano: