Luckily corporations are not the only structures in society. Courts, unions, citizens rights and democratically elected parliaments exist to counterbalance the incentives of the rich.
This is ahistorical. These are institutions that largely exist to settle disputes between the rich and to punish the poor, and came into existence to balance the interests of debtor royals with those of the rich commoners who held that debt.
Corporations were a way to formalize public-private partnerships in which the sovereign would be able to shed the risks of beneficial ventures in its interest, by in exchange shielding private groups taking on those ventures from the normal legal consequences of their actions.
Employer health insurance got its start in WW2 when Roosevelt instituted wage freezes. Shipping companies could not raise wages to attract more workers, so they raised wages indirectly by offering health insurance.
... except the rich can hire enough lawyers to use the courts as a weapon, and in the US, campaign contributions or other rewards for compliant politicians can mean that legislatures are often on the side of corporate interests.
