Which platform is the best? simply this depends on what you are looking for are you looking to fully customize the user experience or are you looking for a reliable but quick setup?
Wix and Shopify are great platforms, however recently with the launch of Corvid, Wix is rapidly becoming higher and more powerful than WordPress at lower development cost.
Shopify can allow for a quick setup with powerful filters, variants, etc.
Wix can allow for a quick setup but also a Corvid expert developer can fully customize the user experience.
We do love both technologies, we have seen developers combining both technologies Wix as a landing page and Shopify as the online store, this has given us a big headache for example what is you want to connect the Shopify product grid with Wix to talk more about the product, this would be a big headache and would require advanced programming with APIs to solve the issue. So our suggestion, choose Shopify or Wix and keep the entire development on one single platform, this will also help the SEO (search engine optimization)
According to Design Rush our agency Stackk is one of the top Shopify designers;