Well yeah but percentage of GDP is just the total spent. The point is that the USA relies primarily on employers paying for the insurance (through a pay cut) whereas in the EU it is generally subsidised with taxes. Which, if you tax fairly, means that the cost of healthcare is better for the average worker (e.g more based on how much any individual earns)
Honestly the French would probably still have a go at it.
Plus it also means that the government has an actual incentive to keep the insurance companies honest