Earlier quoted context omitted.
There are two points to the article. 1) Healthcare spending has rapidly diminishing returns, not only comparing the US to Europe, but comparing countries within Europe (such as the Netherlands versus Spain). 2) The lower life expectancy in the US can be explained mostly by higher obesity. US states with similar obesity to European countries have similar life expectancy.
Re: #2, my understanding from friends at the CDC is that lower life expectancy is due to lower incomes (meaning food, medicine, and doctor visits are unaffordable even with health insurance), suicides, and the opioid crisis. Suicides and obesity can also be caused by low income and drug abuse, so it sounds like the author may be seeing causation where correlation is more accurate.
This is an important distinction.