So things like prototyping, UML, use cases, and Agile were not a "serious attempt" to answer that? I think it's also unwise to tell your manager "it'll be done when it's done."

UML is a description of the engine. It doesn't answer: "do we need our own transportation device instead of taking a taxi?"

You know there is a saying in the creative industry when project managers come knocking on your door.

"You want it know, or when it's done?"

My personal experience is that most deadlines are primarily perceptual.

I think an under appreciated gift Apple has given the world is the patience to provide something when it's done, vs. possible.

Ohh Apple is on a completely different planet.

They follow the principle of "The best way to predict the future is to invent it"

so yes you are totally right about that.

Largely those are things done by developers, not by the business. Perhaps in cases where the business is on board with them (eg. Agile and rapid iterations), but mostly they'd rather handwave and hope for the best.