Society wants cars/antibiotics/furniture/houses/etc but doesn’t want to make them ourselves through our government.
In order to accomplish functions like these that government wants accomplished but doesn’t want to do itself, government “contracts out” those functions. Corporations are those contracts. Corporations facilitate aggregation and manage of resources (huge sums, labor, etc) that are beyond the scope of individuals. We “contract out” through corporate charters to get these things done for us.
When You Look At It This Way
When you look at it this way — that government is the way all of society’s functions are managed(of course it is) and that corporations & the “private sector” are just “contracting out” some government functions — it gives people a way to take back the power in their own thinking. Who is the boss of who? How should corporations be regulated? Who should be regulating them? Etc.
Where Things Went Wrong
Here is where we went wrong. Executives at corporations are allowed to use corporate funds to influence society and pay politicians to allow things that enrich those executives personally.
Everything else we see happening flows from that.