So, out of accounting spite, many companies are opting for churn instead of stability by simple raise vs new hire policy, making it worse for everyone.
That's even more likely to be the case when there are strict guidelines around compensation (eg: when salaries are public). When your manager has some wiggle room, you might be able to justify a bigger bump than average because of all the extra hard work you're putting in, even if your experience level doesn't qualify you for a straight up promotion.
What you’re really saying is that making the information available makes it harder for companies to retain employees using the status quo tactics. Which increases turn-over, which in reality is the businesses problem not the employees. So from the employee perspective what is the problem in being better informed about the price dynamics within the market?
If you’re asking about listing individual salaries, I think some employees would object and, unless they signed onto the job with that expectation, as an employer I don’t believe I’m morally right to publish their currently private information without their consent, nor tell them “you can quit if you don’t like it”. (I have absolutely no problem with anyone voluntarily disclosing their own information, discussing it, comparing it, whatever.)