AI isn't magic, it can't solve problems you don't give it. When doing alpha go they gave the AI all the rules for GO and told it to optimize for those rules. That works fine. But if you want it to make a web-app, what rules would you give it to optimise for? Do you have a web-app evaluator lying around somewhere we can use? If not I don't see it happening.
The current code helper solved that by telling the AI to solve the problem "write code that looks like this bunch of human written code". The AI can do that just fine, but code that looks like human written code isn't terribly useful since the AI doesn't understand what makes the code good, all it knows is that the code looks similar to what a human once wrote. This is cool, but as you can see this is very different from the real deal where the AI solves the real coding problem rather than "write something that looks like code" problem.