Great title, they baited and switched.
95% of the time I don't need effective brainstorming, I need a bunch of ideas, let me pick the best, and move on.
If its a real engineering problem, then I need
>truly effective brainstorming.
They're asking the wrong type of work from it. If you need some boilerplate or a transformation, it's going to give you a fantastic template to work with. If you need it, on the other hand, to engineer out a highly-specific and nuanced solution with an esoteric codebase to a complex problem, maybe not so much. The former is wide, the latter is narrow. It's going to take maybe a bit more breakdown of the scope into proper subproblems before you'll get a good answer; and that's something you can do yourself, or have an agent perform across multiple queries maybe (though I'll admit, more work needs to be done for the whole multi-agent workflows to be truly useful).
Their comment was that ChatGPT can't write final reports but it's extremely useful for seeding brainstorming sessions with real human engineers.
It can generate a list of health, safety, and environmental concerns related to the project that can be distributed and act as a "starter dot point list" that engineers can agree to, expand on, reject as being just silly, and add to as tengential thoughts arise.
I'd argue that makes it useful in the context of real engineering brainstorming .. and that it's being used that way on multi million dollar projects in a billion dollar domain.