When you define too much work up front, you add unnecessary management overhead. More importantly, you create a bias and stifle a team's creativity to solve the problem.

No one defines all the work up front. That's a fools errand. Assuming you know too much up front is the best way to find out you're wrong in the end. Instead we define the direction, the purpose, the reason, and a few specific "must haves" up front. The rest — all the rest, which is mostly everything — is determined during the project, by the people on the project.