And in addition to the rule of law, the US gives it citizens the opportunity to rise above their situation (some would use the term "class"). There are few countries where this is the case. In most countries, the state determines your fate.
European countries have free markets and most have better social mobility than the US. If you check the link in my original post you will see the US has relatively low social mobility for a developed nation.
Your comment reminds me of the attitude described in this sketch: https://www.youtube.com/watch?v=1oyKVAjISmI
There seems to be evidence that Americans overestimate social mobility in the US while Europeans underestimate social mobility in European countries. In practice, European countries also perform better in that regard. https://www.economist.com/blogs/graphicdetail/2018/02/daily-...