This is a massively broad brush with a huge filter bias applied.
1. Many immigrants not from the contiguous countries next to yours were actually rather wealthy and education in relation to where they came from.
2. Immigrants from close countries typically are the ones that are more motivated in the first place (bias filter). It's also common they have relations and contacts in the country they are going to as a means to gain a foothold in the place they are going.
> Many immigrants [...] were actually rather wealthy and education in relation to where they came from.
But they're not wealthy here, and they can't buy the cost of living in NYC or LA with that level of wealth.
With the education point, you're gesturing at something like the real reasons they often outperform very poor Americans (if we compare only equivalent capacity for the sake of argument), I believe: habit, work ethic, drive, belief in improvement. Dom's article about what "poor" looks like makes sense from the inside, but after making it out one looks back and sees all the opportunities everyone around them had to get out of poverty, and it looks a little different, then. Not everyone has all the same opportunities, but a key driver is being open to those that appear, and conducting your life such that they are more likely.
The despair of believing they can't get out of the rut they're in is one of the causes of not getting out of the rut they are in. It's not that the despair isn't real, but it's a self-fulfilling prophecy (and this is true even if they win the lottery, looking at outcomes there).
This is a massively broad brush with a huge filter bias applied.
1. Many immigrants not from the contiguous countries next to yours were actually rather wealthy and education in relation to where they came from.
2. Immigrants from close countries typically are the ones that are more motivated in the first place (bias filter). It's also common they have relations and contacts in the country they are going to as a means to gain a foothold in the place they are going.