I don't understand how the inability to export data complies with GDPR. If a EU citizen decides to use wix and creates a site there, aren't they entitled to all

I don't understand how the inability to export data complies with GDPR. If a EU citizen decides to use wix and creates a site there, aren't they entitled to all of the data they created, and then one should be able to do anything with that data, including converting it to wordpress data ? What am I missing ? The only GDPR related FAQ I could find is mostly focused of wix's customer's customers (IE the site's visitors) getting access to their data, but there's nothing about Wix's customers accessing their data...