The US, UK, EU and realistically most developed countries I would say have fairly similar quality of life within margin of error. I've travelled a fair amount and everywhere is basically the same.
For an individual it's really going to come down to lifestyle and what you prefer. Some people like urban living and walkability, if that's you then you probably want Japan or old world metropolitan European cities. Some people want a house on a few acres and national parks the size of countries, if that's you then you probably want the US.
Working cultures are different but then there is no average on that either. People on HN tend to assume everyone is an office worker or something which is actually a fairly narrow slice of the middle of the spectrum.
Equally though, online (you can see it in this thread) there's sometimes a weird focus on the absolute worst outcomes which I've always found baffling. If you're planning to become a poor fentanyl addict then yeah, don't go to the US, find a country with a safety net, it'll be more fun.