A website is the first pillar for building an audience for your business. It's your home base online.
A home base is not your social media profile, Amazon author profile or any 3rd party social network.
Lets make it simple.
A website is the centre of your online platform, like the capital city of your kingdom. Social Media and other website profiles are the outpost or villages surrounding your city.
Social media is there to drive traffic back to your website. Not to be your main home on the web.