It's fairly common for governments to provide a basic level of care for free or heavily subsidized, but not cover more expensive treatments. It's certainly not exclusive to the US.
At least in Europe and the Nordic systems I have experience with, that typically applies to the very expensive novel treatments. There are gene therapies which can cost $2-3 million per patient and those aren't covered by any public healthcare system, AFAIK.
But it's not like there is some kind of upper limit on coverage. If you have cancer, you will get treatment regardless of how much your care has already cost.
It depends. At some point often it switches to palliative care, rather than treatment. That point is not “there’s literally nothing else we can try”, it’s “the remaining options are inadequately proven, too expensive, high risk, or not effective enough (won’t extend life by long enough or improve quality of life enough)”.
Every single one of those criteria is subjective, which is why you see these fundraising campaigns for kids with cancer to go and a get a multimillion dollar treatment in the US, because as a parent, accepting that there’s more you COULD do if you just don’t give up is hard.
In most of the places I've been in SE Asia and South America, there are separate government hospitals that are the only affordable option for the poor. If you have cancer, they're not going to do much for you.
