That is higher than the 8% the NYTimes quoted in this 2021 article (which I was basing my argument on): https://www.latimes.com/opinion/story/2021-09-14/dont-blame-...
That AMA-ASSN article has a nice pie chart breaking down the high level categories of total health care spending. Though, this isn't particularly useful for understanding why your individual healthcare might cost so much. This article is looking at nation-state level trends, including things like public health activities and nursing home costs.
Labor does make up a massive part of healthcare costs (I've seen it quoted as much as 60%), but that includes every person in the healthcare field. Physicians, nurses, techs, administrators, billing, construction/maintenance staff, security, etc, etc, etc,