If a site is not optimized for mobile or other devices, the visitors feel difficult to navigate or read. But, if a site uses responsive web design, it is not necessary to develop the site for various devices like mobile, web and tablet separately as the website resize itself to fit the device. This will help in better navigation, so the time and money will be saved.
So you think your current website sucks. Your friends and business partners think so too, but they are not too nice to chance to hurt you by saying so. They, however, drop subtle hints about responsive design being in. There lies the issue until you see your website traffic bottoming to an all-time low, and your business leads dropping even lower.
In the connected world we live in, the search is most often done via smart phones and tabs. Desktops are metaphorically moving into the trash of tech antiquity. Like everything else, users constantly seek the experience across devices. Crafting strategy for magnified user experience pan-devices is what sets us apart. Anyone does it.