This is pretty much the long and short of it entirely. And it’s why there shouldn’t be secrecy in salary. The idea that you’re paid your value to the company on-balance gets even more absurd the larger it is. You aren’t an exact quantified line item on revenue vs expense. That isn’t even the criteria except in the abstract or in a very, very small business.

I absolutely agree that people doing ostensibly the same role or with the same job title (but not necessarily responsibilities or time investment) can be deserving of a pretty wide gap in pay based on the particulars but that isn’t the purpose or the reality of trying to keep pay a secret.

Also even if you think you deserve whatever you negotiate, having more information instead of less is probably a good idea during your negotiations.

The only motivation for keeping them a secret at that point is so that your coworkers don’t realize you’re being grossly overpaid for what you do compared to the rest of them and honestly I’m okay with that. Additionally once you get high enough in a company the salary isn’t even what matters or where the money is really made.