I’m Swedish and have worked a lot with / for US companies, but not lived there. I think the reason is a fundamentally egalitarian culture, where crab mentality is not encouraged and people (not just engineers) are fine with working for nerds.

Sweden is kind of the opposite, and it really decimates the opportunities available here. Perhaps not so much in quantity, but in quality.

I mean for my parents, they were discriminated against in their own country (India). Despite all the racism accusations that get thrown around, Americans are much more willing to take chances on people. And then it's very easy to raise your children well here. My parents came to this country in their mid thirties and are well off (retired, own their home, have some disposable income). My brother and I are filthy rich (own homes, multiple in the case of my brother, large investments, etc). We didn't do anything magic. We just studied fields that were high paying, which are open to everyone in this country. People often complain that there's not enough reaching out to various communities. I guarantee you there was no outreach to mine. I'm still the only person I know from my particular background in the United States. My parents were completely clueless as to college and higher education in this country. But if you just take advantage of the free resources and work hard... It's extremely easy to get ahead. I saw so many people growing up simply refuse to take the steps.

It is this particular narrative, and repeated evidence of it among specific immigrant populations, that the American left rails against. The reason is that it means it isn't "the system" it is culture and attitude that makes or breaks success.

The sad part is that, progressives used to care about culture a lot and had great success in these endeavors. We could easily solved poverty if we became okay with forced cultural change. Of course this is a hard sell in modern America. But it wasn't even just a century ago and progressives were it's biggest proponents.