In short, it’s very important!
Google has moved to a mobile-first index, meaning that the mobile version of your website will become the version Google will use to determine search engine rankings. Not only that, but consumers depend on their phones to answer search related queries, especially using Siri and Google Maps to find a business quickly and in their proximity.
Optimising your website for mobile devices is critical to promote an efficient and positive user experience. At the end of the day, you want to make interactions with your business, as easy for your customers as possible!