Wealthy, aging boomers with increasing need for health care, makes sense.
Americans of all ages are spending more on healthcare, and seeking more healthcare interventions than in previous decades.
i.e. young americans are spending more on health care than young americans used to, even if it's also true that there are fewer young americans now, and more old americans.
In 1860 someone who went to a doctor would have worse outcomes than someone who stayed home. As medicine gets better over time there is more and more value in seeing a doctor. In turn more an more people are talking to their doctor about things that they would have just ignored a few generations ago. Sometimes this results in unnecessary treatment, but it also results in catching and fixing a lot of real problems that would have made life worse before we could treat it.
Americans are spending a lot more on quality-of-life medical interventions, many of which are outside the normal standard of care that would be covered by healthcare systems. It is a booming business in the US and many people seem to have no trouble paying for it.
My main caveat / counter point is that preventative care may actually increase as more and more people jump on the live for ever, dont die, longevity hacking trend.