Earlier quoted context omitted.
It's not just boomers (though they are the biggest part of it). Americans of all ages are spending more on healthcare, and seeking more healthcare interventions than in previous decades.
This isn’t surprising. The population overall is aging. Millenials are now the largest cohort and are approaching middle age. Until recently we’ve seen the number of insured individuals rise consistently and our medicine continues to advance. More older adults have access and need more healthcare
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.