First, you admit that "you and everyone you know" live in Europe. Perhaps consider not making sweeping generalizations about places that neither you nor anyone you know live.
Second, the many US States are far from perfect, as are the many EU member nations, but conditions in the US in general are hardly "shitty."
Other's have pointed out the extraordinary number of immigrants to the US -- there are more immigrants living in the US (40M) than citizens of Poland (38M)[1]. Those are normal people making intelligent, reasoned, self-interested decisions. They didn't leave their homes behind for a downgrade.
But more to the point, generalizing "conditions in the US" is utter foolishness. The US is very much like the EU v0. In the same way that my time living Italy didn't give me a great deal of insight into life in Belgium, a stay in New York City doesn't tell you very much about life in Idaho, or almost any other place in the US. The states are highly autonomous by design, and life experiences vary widely between them.
Yes, New York and San Francisco in particular are having a hard time due to acute housing crises, and some other cities are dealing with housing issues to a lesser extent. Yes, healthcare here is a problem if you don't have insurance.
But fortunately, the majority of the country is not SF or NY, and 92% of people have health insurance[2].
1: https://www.pewresearch.org/fact-tank/2020/08/20/key-finding... 2: https://www.census.gov/library/publications/2020/demo/p60-27...