For a start, you might want to google up Medicaid.
Insurance protects one's financial assets (to some extent) and gives a patient more healthcare options (to some extent).
The system is messed up, but it doesn't mean the poor are left on the curb to die. On the other it does mean a middle aged guy with a house that is paid and wants to do without for a bit is taking a greater gamble than a kid with $3000 in the bank. Everyone,s situation is different, of course.