I can't show real world numbers when the phenomenon in question can't have controlled experiments run on it, and I don't need to show real world numbers to make

I can't show real world numbers when the phenomenon in question can't have controlled experiments run on it, and I don't need to show real world numbers to make a case for the logical soundness of a principle, in this case the principle that prioritizing improvement of a metric other than overall performance will generally lead to less overall performance improvements than not doing so.