This is a common question now that social media seems to have taken over the internet.
Yes, you still need an online presence through a website, you need to showcase your shop, you can have more in-depth descriptions of products and services. The social media channels are your marketing tools, if used creatively you can bring in huge audiences. Customers and clients get enticed to your website through the social media channels they see your products and services and want to know more about your business, having a website gives you stronger credibility.