The reason someone has to risk his life to get to the US could be because the US is the greatest country, at the same time you could also consider the influence that the US in its history has had on other countries so that the life of the people are miserable there.

(e.g. backing and installing dictatorships[1], contributing massively to climate change, ...)

[1] https://en.wikipedia.org/wiki/Military_dictatorship_of_Chile