Except healthcare! You're required to buy it in the US now, but regardless...the hospitals would negotiate with insurance companies to <50% of the bill (and I've seen >90% reduction)- you can't do that as an individual and will generally be stuck with the full price.
Health cost can very easily ruin you, even if you are quite well off. Even the possibly better prices negotiated by insurances for a serious illness are ruinous, and keep in mind you most likely won't have an income while you're seriously ill. Reduced cost in the US is just icing on top.
So everyone definitely needs insurance for healthcare.
Ah, I think you misunderstood my point. I was specifically saying that getting health insurance was important- even if you have enough money to cover the cost generally. I mentioned insurance negotiation to emphasis that there were outside factors contributing to making it must-have.
