Hence, blockchain could help those poor helpless Americans to reach to world standards with the obvious difference shown on blockchain and make hospitals liable for extra charges.
Yes, healthcare in the USA is broken, but blockchain technology isn't some magic bullet that can fix that.
There are already plenty of places where you can see the price differences between hospitals, such as the Office of Statewide Health Planning and Development for California:
https://oshpd.ca.gov/data-and-reports/cost-transparency/hospital-chargemasters/. The issue isn't that one hospital is charging $50,000 for a caesarean section while another is charging $52,000, or that one pharmacy is charging $1,000 per month for insulin while another charges $1,100. The issue is that the real price of a caesarean section is less than $2,000 and the price of a month's supply of insulin is $20.
The issue with healthcare in the US is that it is run entirely for profit by the corporations which control it - people are seen as customers to spend money, not as patients needing care. Until these influences are removed, American healthcare will always be horrendous. Blockchain won't fix that, and even if it could, the corporations would never let it in if there was even a sliver of a chance of it cutting their ridiculous profit margins.