I’ve been developing responsive only websites for over a year, and it is becoming more and more important these days.
There are a lot of design and UX/UI issues that need to be thought of before jumping in. Thinking mobile first can be quite the effort when you get started, but as time goes by it gets easier.
There are a lot of reasons to go responsive. Here is a great inforgraphic that distills the key reasons why a website needs to be designed in responsively.