> if someone claimed more than a few decades ago that certain economic strategies and structures are good or bad

As you point out, it is all game theory.

But things that arrange for the game to be more beneficial to everyone, that align our interests more, deserve to be called "good", regardless of their inability to universally do so.

The latter would be an impossible bar for anything.

Where I find things frustrating, is when someone thinks because something is "good", it somehow becomes "enough". (Think, capitalized versions of different economic schools of thought.)