What does similar quality mean, it they're different in multiple axes? Maybe one is easier to use but the other is faster, or one is better tested but the other

What does similar quality mean, it they're different in multiple axes? Maybe one is easier to use but the other is faster, or one is better tested but the other is written in a more modular way that won't require big refactors to make changes? This is the crux of the problem, I think, programmer output can be analyzed in so many different axes that have different weights in different industries that measuring productivity objectively is incredibly complex.