The checks and balances in the US were always rather fictional, but this particular failure mode of big corporations being able to cause vast amounts of harm and suffering, completely disproportionate to any benefits to the society, seems to be intrinsic in any state of matters where big corporations are allowed to exist at all.
However, there are certain aspects of the US society and political system that appear to be particularly well suited to the rise of big corps doing big evil things.
Big Oil has been an immense producer of _value_ to society. It is fossil fuels that has enabled so much of our modern world to be possible. Cheap, portable, effective and efficient production of energy at scale. My goodness. The ancients would be so jealous of what we have - and so confused by our reaction to what made it possible.
What an amazing achievement for the liberation of everyone.