That makes me think.

I never really worked with a PM that was good at preventing wasted effort. Or even mediocre at it. Most assumptions I saw them making were incorrect, unless it was a VERY SIMPLE product.

To me this is something that engineering should be doing, just like splitting tasks and double-checking designs.

Of course not every engineer can do it, but some of us have been doing it, negotiating deadlines and deliverables our whole careers. So I don't really understand why our industry insists on having us throw away those abilities.