> You find your coworker makes more money, you ask for more.
I used to believe this when I was younger. Many, many years ago I used to work for research team a state university. In most states all public employee salaries are public data and there are watch dog groups that collect this and post it online. Right now if you have a friend (or enemy) working at a state university you can probably find their salary.
While working there, there was an IT/tech staff that was pretty incompetent who most people gave a really hard time. This person didn't have much formal education and didn't understand anything about their role, but I and some others always felt that "hey, they get paid next to nothing so don't give them such a hard time."
Then someone looked up their salary and found they made more than most of the junior faculty in that department. The result wasn't a wide spread demand for more equitable pay, but universal anger that this kind but lazy employee was making more than the majority of the department. As much as I hated it, I myself immediately lost all pity I had for this person.
End result was that nobody got paid more, and if we could have voted we probably would have argued that this person should have either been fired or paid less. Even if in theory workers should stick together, and even in an academic dept where most people understand this theory, we're still trained to turn against each other.
In my experience the best way to share salary data is anonymously. https://www.levels.fyi/ radically changed my salary requirements, and it's incredible how many young people working in tech have no clue how much they could be asking for. Whenever I end up mentoring a junior tech worker I always make sure they understand how tech compensation works and what the upper bound really is. Most react at first with anger that they get paid little, but nearly all negotiate much harder when applying for their next job.
Information is essential to increasing worker pay, but personal information can only result in pettiness and strife in my experience.