He's wrong. There's no such thing as a CRUD developer. No one would pay someone just to make essentially GUIs for the database tables. Also CRUD is ancient history, webapps are all interactive react now. CSS is hard. Also AI-generated CRUD or even CSS would be hilarious, I want to see that.
Another thing though, web apps are not all interactive React now. That's falsified information. There are multiple cases where webapps aren't even backed by React. Webapps are still being built in CRUD frameworks.
Yes, but no one is hired to just make CRUD apps. Those are like 10% of the work that needs to be done to maintain a business. Just throwing in authorization/authentication provides enough "house rules" (business-specific rules) that AI would have trouble with it.