That's a great point.

My only counter consideration might be that one's resume which states:

"I built XYZ at $COMPANY and resulted in $Xm in revenue growth" and one could simply show the person the product or area under which professional worked.

Per your point regarding candidate pool to evaluate, would you consider it fair to say that you see the purpose of the live problems and technical projects as a means of normalizing the ground of analysis (i.e. comparing apples to apples versus apples to oranges)?