Greed is a very human emotion, corporations are like very powerful sociopaths. No-emotion machines that optimize for a single end goal (shareholder money) within the given ruleset: the law.
(Or more realistically whatever they can get away with while still turning profit, ie profit is greater than whatever the repercussions cost).
As parent said, corporations are restricted only by the market and by the legal system, so it’s up to the voters to implement effective taxes and rules as needed
The actual people have no say whatsoever.
Because that's what this Princeton study found: https://act.represent.us/sign/the-problem
We live in a plutarchy disguised as a constitutional democracy sold to its employee-citizens as a democracy.