I will add here that my biggest disagreement is treating a website hosting platform as some sort of proprietary content. I understand if they don't provide an export of their theme. I understand if they don't want to provide an export in some nice-to-use format. IANAL, but not allowing any sort of export at all should be illegal. At a minimum, someone should be able to email Wix support and get a CSV of the data _they created_ on the platform.

The owner of the website is the copyright holder of the user generated content. The fact that they would have to go and copy/paste their own work, download their own images, etc. in order to move to a different provider absolutely cements my position to actively warn people in my sphere of influence to avoid Wix like a plague. The gall of a company to exploit the OSS parts of the web and to only take & take without ever giving is gross.