Do you have personal experience with fully private heathcare systems in other countries? I ask because reacting to criticism of your system with whataboutism concerning the US is not rational, that's a fallacious argument.
As for the US I'm not an expert but my gut feeling is that people compare apples to oranges just like with most of these international comparisons. Cost of living is much higher in the US first of all. Things are simply more expensive in general and American salaries are a lot higher for anyone moderately educated. No one I know who's moved to the US has any problems with insurance, they can simply afford it.
Now if you compare a government sponsored system in Germany with private insurance in the US, of course the former will be cheaper (be careful though, some of the real cost is hidden). But like mentioned you also get completely different treatment. Cost in the US could likely be cut by making the service worse. If you want to pay even less, have you looked at the Chinese system? Germans are massively overpaying in comparison to the PRC and it's ruining the middle class. /s Gotta sinophy your healthcare with 10 Yuan TCM pills for cancer treatments. Because cheap is apparently the goal when it comes to healthcare.
Btw, here's the kicker if you want to discuss price: With the top notch treatment you get in private South African clinics, people still pay less for their private insurance over there than the government mandated low quality one in Germany. I know because I've used both.