My impression is that blood cholesterol issues are so common in the US that every primary care (general / internal / family) physician is very familiar with them, so why would a cardiologist be needed if that were the main issue (as opposed to more unusual cardiology problems)?
In the US, pediatricians are the usual primary care physicians for kids, not additional specialists beyond a regular primary care physician (as opposed to pediatric cardiologists, etc.). They also are not paid higher than other primary care physicians.
However, US physicians often carry high educational debt burdens compared to those with medical education in other countries.
This is also hinted at in the US. For example, US socialized insurance for the elderly (Medicare) covers annual wellness visits, and says that “The yearly “Wellness” visit isn’t a physical exam.” But that was not a popular concept when it came up in some other thread in these forums.