The problem I've been having is they just have no sense of systems, which is exhausting once your app scales to anything beyond 1 page. It will happily write features that can't interact together at all, despite being in the same piece of software, and burn tokens to glue them together when you point out the problem.

And obviously you can say, "hey these features need to work together make no mistakes." But for really big projects like professional software, that's a LOT of features with a LOT of possible interactions.