It shouldn't be that difficult to generate back-end code for say a Bootstrap template. It should even be possible to generate both a Bootstrap template and the corresponding back-end code from something like a Balsamiq mockup.
The problem with generated code though used to be that it tended to both break quickly when confronted with non-default requirements and to make customisation by (human) developers much more difficult and cumbersome.
So, perhaps the route to having largely automatically generated CRUD apps isn't so much paved by the code generation process - involving AI or not - itself but by how easily the generated code can be extended afterwards. I'm envisioning to never have to touch the actual CRUD code. I'd rather like that CRUD code to provide extension points for additional services or functions to tack on to.