Then let's disregard cost of running and maintaining a system for having exact financial feedback.

We do proxy measurements because having exact data is hard because there is more to any feature than just code.

Feature is not only code, it is also customer training, marketing - feature might be perfectly viable from code perspective but then utterly fail in adoption for reasons beyond of Product Owner control.

What I saw in comments — author is selling his consultancy/coaching and I see in comments that people who have any real world experience are also not buying it.