Smith makes his case. He is the father of modern economics whether or not you subscribe to his beliefs or not. The question of equity specifically is addressed in the passage:
No society can surely be flourishing and happy, of which the far greater part of the members are poor and miserable. It is but equity, besides, that they who feed, clothe, and lodge the whole body of the people, should have such a share of the produce of their own labour as to be themselves tolerably well fed, clothed, and lodged.
That makes measurement unambiguous and shows the failure of your multiple assertions otherwise.
The values you propose of "accuracy", "efficiency", "dignity", and political vs. economic concerns (Smith clearly combines the terms) are equally if not far more arbitrary and poorly supported by empirical evidence.
I'm not going to spoon-feed him to you, though the curation of passages posted above would be an excellent starting point for one actually capable of benefiting from exposure.
The main value I'm proposing is "consent". It's rather less arbitrary than "flourishing" or "happy" or "fair". The basic premise is that all human interactions, relationships and associations ought to be as consensual as we have realized romantic ones ought to be. You're no more entitled to a surgery or a loan than a partner. If you disagree, then all I'm asking is from where do you derive the entitlement?
You've not described how my views are amoral either. What's wrong with consent exactly?