I think I laid that out pretty clearly in the prior comment, is there some part of it that's unclear?
I feel like we’re talking past each other. Sorry if I’m being dense.
Yes, emergency care has been essentially free in the US for those who can never pay for it, but that doesn't cover, say, chemotherapy. If you don't have insurance and don't have any way to generate significant cash (no house to sell and no wealthy generous friends) it's not that you're going to get chemo and it'll bankrupt you; you just won't get chemo at all (and you'll probably die). This is a little better now with the medicaid expansion, but not perfect, and not all states expanded medicaid.
Even today we have people dying of complications related to diabetes -- a serious but very treatable affliction -- because they can't afford supplies. In the US! The world's richest country!
While everyone in America can receive emergency treatment no questions asked it isn't necessarily going to happen very quickly and can result in more health issues than being able to pursue medical care through more standard means.
The people who went bankrupt before were generally those without insurance. You've not said anything that explains to me why they wouldn't do the same under this supposed new system.