> This immeasurability is inversely proportional to the tangible, real value created.

I don't think that's true at all. Certain kinds of value are more easily measured, sure, and if that's all you mean by tangibility, what you say is a rather trivial tautology, but there's times when the value is real and tangible and easily qualitatively described (e.g., reduced workload), but tricky to measure because to accurately measure the increase you'd have to measure against a set of hypotheticals (e.g., cost/performance using best alternative of continuing with the status quo ante or competing automation options, including alternative custom builds.) For certain types of value, this is irreducibly true for many of the same reasons intellectual work is well established to be difficult to estimate accurately (this actually converges to an identical reason when what you are doing is building automation to support intellectual work.)

And even when productivity is measurable, it's often not easily measured at the time of delivery ; where the problem is measuring hypotheticals but the only problematic hypothetical is performance with the software, it may take considerable real use before the actual value is clear.

But, it also can be unclear the value of any individual contribution even when the aggregate product value is clear. Telling the value of what the team delivered is different than trying to peel out the value Bob created.