If you actually are better then you’ll negotiate better pay.
You’re saying the equivalent of “I don’t want a free market. If other people have the same information I do then I won’t be able to benefit off the information disparity and have to compete on merit”
That's absolutely NOT how it works in practice. It is widely studied that there are HUGE differences in programmer productivity. While the theoretical "10x" programmer may not be that common, I see "2x" programmers all the time.
But you hardly ever see 2x differences in salaries, even though this would be the fair thing if you were looking at output. Once pay becomes public, management is basically constrained to keep people in relatively tight bands because it's trivial for anyone on the lower end of a pay scale to complain that Programmer X gets paid more money, even if Programmer X gets shit out the door 2x faster.
But I don't think you are claiming there are not significant differences in productivity? Given that, it's not unreasonable for the more productive people to ask for more compensation, even if it is difficult to identify who they are.
It's definitely a hard problem. There is probably a lot of room for improvement in general for how we approach this.
That said, while it can't be measured, I also don't think anyone would disagree that it does exist, in that I've easily see engineers that can produce reams of quality code in a fraction of the time other engineers can produce buggy code.
But yes, I do think there is an amount of judgment at the end of the day, which is why this is a tricky subject.
If a trivial complaint from a colleague who, in your theoretical here, is less productive than you can make your employer not pay you more then that means you are only trivially more productive or negotiating pay based on something other than productivity.
Labor is told repeatedly that wages are based on market forces and companies have to act at a sociopathic level of responding to economics.
Why does the narrative always flip to employers having to act emotionally whenever labor would get an up like decreasing the information asymmetry between employers and employees?
While I agree that there can be or at least seem to be that overall difference in productivity between people, utilizing a single metric to make that conclusion is simplifying a much more complex issue.
Or a senior dev may wind up only getting a few tickets done, but it's because they're dealing with meetings and planning to determine the correct course of action for a project that may take a month or more. Or they may be a useful 'repository of knowledge' for the rest of the team, and spend a lot of their time enabling multiple other people to be more effective than they would be otherwise.
If you mean that, between people in the same role, there is usually huge differences in productivity, I honestly haven't seen that, except perhaps for brief periods where someone is late to a deserved promotion.