Most of the US has a low cost of living compared to eg Switzerland. In most of eg Texas - most of the US actually - you can live well on $50,000 to $60,000 per year.
You're aware I'm guessing of the economic metrics of the top 50% in the US? It seems obvious to me that in fact you do not have to be mega rich to live well. The top 80 million Americans in the labor force would likely qualify as having at least as good of a life as the median Swiss standard of living.
You won't get >4 weeks paid vacation in "most of eg Texas", or actually affordable healthcare, or paid maternity leave (let alone multiple month worth) and post-leave work-hour arrangements, or a "sacred lunchtime", or the ability to work flexible hours without being looked at like a loser (unless you're self-employed maybe), or 80% salary unemployment, or the ability to live without owning a car.
A privileged few may get those. Not "most of eg Texas", not by a very, very long shot.
Beyond that the differentiators are working hours/flexibility and healthcare. A household in Texas might have quite a good life in many respects with an income of 60k/year, but do they get 6 weeks off, flexible working hours (useful if you have kids), and paid maternity/paternity leave that lasts more than a few weeks? In the US if you want/need that extra time away from work you might need to take time of work or go part time, causing a drop in income and perhaps company sponsored healthcare, but in many European these things are available by default to fulltime employees.