Not really. The tradeoff is not just for money but for a spectrum of compensation, which could be equity (which could confer voting or board rights to you to monitor certain things about the company financial health), vacation time, conference attendance, foosball table access, etc.
Often these things are negotiable, at least if the employer values talent. So why couldn't we negotiate that part of compensation is some sort of verifiable transparency and mutual respect in terms of monitoring the appropriateness of company activities (whether on behalf of the employer or employee)?
I don't see any fundamental reason why these couldn't be negotiated as part of an employment agreement. Instead, what I see is that most employees either don't know or don't care about these items, and, more importantly, that employers actively collude and engage in e.g. regulatory capture specifically to deny workers the opportunity to be able to negotiate these things.
If you have that, then you have significantly elevated access to the information you were talking about, and you're already landing on the side of protecting the company. The issues you raised don't really apply here.
> [...] vacation time, conference attendance, foosball table access, etc.
If you value those on par with your salary, then I have a job for you! ;)
> I don't see any fundamental reason why these couldn't be negotiated as part of an employment agreement.
You're right, there is no reason. You can and should negotiate these things. Negotiate away!
Just recognize that you may have multiple conflicting interests within yourself. If you want access to confidential company information about others, you're implicitly requesting that they have access to confidential information about you. Most of us wouldn't mind knowing everyone else's salary, and most of us don't want others to know ours. Most of us would love access to the personnel reviews of our co-workers, and most of us would be mortified to let them read ours.
Those things are worth some fraction of salary, at least.
The issue of symmetries of power brings into call the granting and enforcing of rights at a very basic level. If rights are not endowed in a symmetric fashion, shouldn't we step the conversation back and talk about that instead of throwing our collective hands up and agreeing to participate in perpetuating institutionaled inequality?
Your primary agreement with the company is a trade of your time and skills in return for money, and the symmetric right you have is that you definitely do have the right to monitor and verify that you've been given the proper amount of money.
> HR files could be misused [...] so why aren't such files open for inspection?
In some places, they are open for inspection. There are laws in at least some US states that the company must show you your own personnel file, if you request it.