This isn’t true at all. Insurance is heavily regulated. If you can’t resolve an issue with your insurance, most states have arbitration committee that will smack down insurance companies pretty quickly.
Crucially, that's only true if you have the money and time to fight. For the people hurt worst by the system, they lack some or all of: knowledge that they can fight it, money with which to fight it (or again, knowledge that a lawyer will take it pro bono), and the time with which to fight it and not work one or more jobs. I know people on this forum are relatively well off, but everyone reading this should try to put themselves in the shoes of someone working multiple jobs, trying to take care of a sick family member, and facing predatory companies trying to bilk them for all they're worth.
That the government will protect you, in theory, is not the same thing as in practice.
