According to this chart[0], world healthcare spending was $7.7 trillion in 2016, of which $3 trillion (39%) was spent by the USA. The USA really does do most of world healthcare spending, disproportionate to its population.
Revenue on it’s own is meaningless in this context. All those US drug advertisements are paid for with US heathcare spending along with endless paperwork, insurance profits etc.
~$30 billion / 348 Billion is not (1% of US drug spending) Of note prescription drugs are not the only medical advertising, but they do represent a rather large share.
Population creates limits for the amount of useful medication that can be provided, inefficiency is practically unbound. It’s not that on it’s own say Heath insurance overhead and profit is that expensive it’s simply yet another implementation detail unrelated to actually providing heathcare.