Exactly. One of the fundamental tenets of science is reporting estimates with appropriate precision, e.g. significant digits. If the probabilistic interquartile range spans multiple months, why would I report the mean of the estimate in "hours of effort"?

What's frustrating is I've articulated these thoughts clearly to managers in the past. They nod their head and agree and then ask for the hourly estimate again and we all collectively share our disappointment when our estimate is inaccurate after the fact.

Nothing like running head first into a wall and expecting a different result.

My management suggestion? Frequently identify and advocate for simplifications, and modulate the degree of simplification based on progress to date. If people enjoy their work, they will work hard regardless of timeline hawking. So the variable factor is really the volume and complexity of work, not worker intensity or motivation.