The fact that this is constantly debated is sad. I've run numerous tests across various organisations. When measured it becomes evident that 10x is nothing strange.

Set some real world useful target. Give the task to individuals or small teams and let them go at it, with regular followup. Measure time, defects, maintainability, whatnot. Perhaps add some real world change of requirements mid stream? I've seen solutions ranging from hours to never.

What I see, and find very sad, is that most organisations have obstinately obtuse attitudes and handling of such simple analysis.

It doesn't matter if the variance stems from intelligence, creativity, work pattern, experience, clever tricks, tools, processes, etc, etc. If it's faster/better then find out why, and learn from it. Can it be taught to others? Change work processes? Hire differently? ???

Whatever works. But ffs: measure, analyse, learn, embrace.