I know of Indian immigrants who suffered for decades/years on H1B, endless anxiety and tensions, eventually make it to GC, then a passport.

Then all of a sudden fall ill, lose everything and return back to India.

People keep forgetting the US society is a giant stack/pyramid ranking system, the structure keeps getting narrow as you move upwards. You get pushed off the sides, in the ever narrowing funnel, and you need increasing levels of luck at every level to survive.

BTW, this is not just with regards to health care. You could lose your job, suffer from ageism. Lose your home, run out of money. A million different things can happen, that can cause the above said phenomenon.