Creating a responsive design for your website is very important today. Not only that the world is going digital, but we are frequently using different devices of varying screen sizes - laptops, PCs, tablet and mobile. For many of us, we have at least two different devices that serve our particular purposes.
Before, this is not the case. Sure, you may have a phone and a computer before, but you use them differently. Apparently, there's no mobile internet before, so you purely use your phone for texting, calling and perhaps, as a camera tool. This is clearly not the case today - we use our different gadgets for mainly the same reason (usually for Internet browsing).