Because at the end of the day "equal skills" doesn't exist. You can't just measure a developer's overall skill with a single power level number like in some anime. Different people are good/bad at different things and two engineers at the same level/experience can contribute to the team in completely different ways.

That's why compensation exists in bands, which is aimed to reflect that skill levels exist in bands (not all L4s are equal, etc).

Also some kinds of compensation are intended to keep you for the future, and some are for past efforts, and not all of that is about "skills".

Equal purely engineering skill no? There is more to bring an effective engineer than a coding metric

The parent specifically said "I'm not (and don't ever expect to be) paid the same as other equally qualified engineers on my team."

I understand your point, even if I think it's a little narrow, but the original comment seemed to apply that there was no point in even trying to achieve equal pay. That just totally baffles me.

Equal pay forces metric-based assessments which imo is detrimental. I think(?) that's what op what refering to. It's incredibly hard to evaluate how to pay 2 different people, allowing negotiation allows the free market to determine the price, which is the best way we have found as a society to allocate assets.

There main point following some of there other comment is

equally qualified != equally performant