By contrast I agree with your second example as systemic discrimination is something sharing salaries can directly help with. I had a female co-worker who was the same level of engineer I was at our company, had more experience and a Master's degree (to my Bachelor's), and was making 10k less a year than I was. Now I'm not sure if that was due to her being a woman or being rather conflict-avoidant (or both), but seeing the difference certainly made her push for a promotion that she eventually got.
One potential reason: being aggressive and strategic, as qualities, are orthogonal to one's skills. They're just as good signals for being an abusive manager or manipulator as they are for "giving a damn."
We've also gone and conflated "aggressive during salary negotiations" with "(positively) aggressive in one's job." It's not clear to me that these are the same things, particularly in the context of economic need and privation: I'm more likely to be aggressive and confident in my job once I know that I can afford groceries and rent. The "I" there is me, personally.
In sum: the qualities that make someone a good negotiator in the context of obtaining a job are not necessarily positive qualities within the context of the job itself. Conflating the two eliminates an entire cohort of qualified people who may possess those traits but lack the systemic comfort to risk demonstrating them.
1. Accept the offer
2. Walk away
3. Say "How about more compensation?"
If you do 3, the company will either say:
3a) (95% of the time) "How about no?"
or
3b) "How about this small amount more?"
And from there you can accept or walk away and that's pretty much it. You can write the decision tree on a post-it note. What are people talking about when they say "aggressive and strategic"? Bang on the table more? Yell and scream? What are you captains of industry doing that the rest of us aren't? In my view, we are just workers--our only leverage is our willingness to walk away, which is usually fine with the company. They have a long line of candidates out the door.
Over the course of a career this behavior compounds into superior experience, superior interview performance (you have more examples to draw on/confidence in general), and secure enough position such that you have the ability to walk away.
For example, your perspective of "they have a long line of candidates if you try to negotiate". That may be true but your name arrived at the top of the list somehow. The fact that you're getting an offer alone gives you some leverage, and small increases in salary can matter over time. There's always a range of salaries for a given position, why not convince them you deserve the top of that range? Maybe it's through actual experience, maybe it's just by reading their personalities and being likeable in the interview, but at least try the hand you're dealt.
Granted this isn't always possible given an individual situation, but so many people simply throw away what leverage they have out of anxiety.
You have more leverage than that; not all workers are equal. That's why interviews exist in the first place. Maybe you have prior industry experience, or experience with some paradigm/framework they want to adopt. Feeling like that probably hinders you in negotiations; if you're arguing that workers are largely interchangeable, it begs the question why they would hire anyone other than the cheapest possible person.
On your decision tree, you're missing a step where you explain why you're asking for more pay. The most compelling argument there is frequently a competing offer from another company for more money (which is evidence that what they consider "market value" for you is too low). Other than that, you can argue that they're misjudging your value to their company. Your industry experience should add value, or your ability to be a leader among ICs, etc. You'll have to justify why you should be paid more.
You've also entirely left out negotiating. If you're not happy with response 3a or 3b, propose an alternative. There are several compensation alternatives to salary.
In terms of pure cash, you can ask for a sign on bonus. Those are typically paid out of a different pool than salaries, and can be easier to negotiate than a salary increase. It's also CAPEX instead of OPEX, which I believe is preferable to a business (just based on what companies have told me, I don't know the entire reason why other than that it's a 1 time cost). If you have an idea of how long you'll be at the company, you can amortize the sign on bonus as part of your salary.
There's also a large array of non-cash compensations you can get. You can negotiate to work from home X days a week. You can negotiate for more vacation days per year. You can negotiate reduced hours for what they're paying. You can negotiate to have them send you to conferences, or to more than the standard number of conferences. You could probably have them give you hardware that's being decommissioned if that's your thing. Another atypical idea would be to have them pay for/subsidize/use their discount on an AWS/GCP homelab for you (that seems less likely to be possible because of issues with accounting, but can't hurt to ask). The limit is only your imagination.
I think aggressive is a misnomer here. I would call it assertive. You don't have to bang your fists, just know what you're worth to the company and maintain that you won't accept a lower value. If they say they'll pay X, you respond that it's below what you would expect for someone with your skills/experience/whatever and that the offer would be more compelling if it was $Y higher. What many people do is the opposite; they wait for the company to decide what they're worth and then they decide whether that valuation is acceptable to them.
If you've just been laid off or are fresh out of college and "need" a job, then maybe being aggressive isn't worth the risk. But once you have an established career being positively aggressive on the job largely determines the opportunities that present themselves and the will/ability to exploit said opportunities. This in turn compounds into more favorable experience and a more secure position when applying for the next job. It's basically what the buzzword "leadership" is supposed to mean and why it's a buzzword in the first place.
To your point, filtering for those traits does filter out a large cohort that may be qualified for the job, but a company is more than just the job they offer. Do you want a worker who does his 40 and goes home every week, or someone who might bring extra dynamism and productivity to the company on top of his 40, and is only asking for 5-10% more?
How is that relevant to the person’s compensation for their work? Yes, negotiation might be a useful skill in other areas of life, but you might as well advocate paying people more for other useful skills that are irrelevant to their effectiveness at work, like changing a tire or home cooking.
Because being "aggressive" and "strategic" are not the only two qualities useful to providing value to an employer. Hell, depending on your role, being aggressive can be a negative.
Wonder if a different colleague making 10k less had shared salary if she would still have pushed for the promotion ?
Is there a lesson here?