Responsive design not only lets you control how customers experience your content. It also lets you decide what content your visitors see, based on the device they’re using.
People looking at your business website from a phone likely want contact information. So I may put your phone number and address front and centre on mobile devices. Whereas, on desktops, users have more bandwidth and larger screens. So you may serve hi-resolution product images, and put contact info out of the way.
Responsive design is one way to deliver the right content at the right time.