From the company's / management's perspective I suspect this is an issue as well. If salaries are transparent then higher and lower salaries need to be justifie

From the company's / management's perspective I suspect this is an issue as well. If salaries are transparent then higher and lower salaries need to be justified beyond "they negotiated better". Similar to pay raises. Now if the delta is known, why someone got x% and I got less than x% now requires more delicate conversations. Netflix directors and above can see all salaries though. I wonder how that's working.