All of the websites I create are built on WordPress. Why? Because it is the best open-source content management system (CMS) around and currently powers over 34% of all websites on the Internet (wow!). It is constantly being developed, improved and strengthened by developers from all over the world. But what makes WordPress truly great is its flexibility and ability to be customised, rather quickly compared to traditional website development. WordPress also allows you, the website owner, to make changes to content, add blog posts and more if needed through an intuitive and easy to use interface.
I currently do not work with Wix, Shopify, Squarespace or any other website builder or CMS. However, if I believe that one of these solutions is a better option for you I will let you know.