It seems to me that the numbers don't lie. Either the tool is producing value (additional revenue, fewer costs) in excess of its cost, or it isn't. I don't think you need to be adept at technology to make that evaluation.
How do you measure developer productivity? Code quality? Developer happiness? As far as I know, no one in the industry can put concrete numbers to these things. This makes it basically impossible to answer the question you pose.
There are of course many factors at play here, and a substantial percentage of CEOs report a positive RoI, but the fact that a majority don't shouldn't be dismissed on the basis of this being difficult to measure.