You obviously know this, but for those who are not familiar with America, regarding #2 above, the experience in the US is vastly different from other rich countries.
> The lower threshold for the U.S. is $23,416 PPP-adjusted 2010 dollars per year.
A person that makes this in the US usually will not receive health insurance at work. Depending on the specifics of the person's demographics/state/income, a worker at the boundary between "middle income" and "lower income" may not be eligible for ACA subsidies and may not make enough to pay premiums. The middle/lower part of the income range is where a lot of the uninsured live. Jobs that pay near this boundary also tend not to come with real health insurance. So the frequent debate about repealing the ACA means that even if they are insured today, these folks do not have any healthcare security as the nation actively debates repealing their lifeline. (IIRC the Supreme Court will decide this summer whether millions of people lose their insurance this year. It's not a sure thing either way.)
My personal take is that not until you're fairly rich (upper middle class) can you attain roughly the level of healthcare security that comes with residency in other rich countries. And even that requires you to stay employed, so it's still a lesser quality of security.
Similar factors apply to the rest of the safety net. The US might be the worst rich country to live in if you're low-income/modest income.