How do employers justify touting "competitive" wages as a legitimate comparison of pay while condemning wage comparisons among employees?

When employees cite the wages their co-workers earn as a benchmark to compare their wage to, employers denounce it as irrelevant because they claim that every employee is different and they say to mind your own business.

BUT

Somehow, these same employers consider wage comparisons among employees in DIFFERENT COMPANIES as legitimate...they just call it "competitive" wages.

How can they justify their claim that what employees at various different companies earn is more relevant to what one of their employees earn than what their coworkers doing the same job at the same company earn?

How can a company logically use wage comparisons for the industry to tell you "you make enough", while simultaneously telling you that wage comparisons that are objectively more relevant because they do the same job at the same company are irrelevant?