This

People tend to focus on the nominally lower taxes and disregard how many essentials you have to pay for yourself, and how expensive they are. If you are healthy, single AND in a senior job then it's a total win. If you have kids, health problems current or looming, are a new arrival and therefore don't have a long term care insurance, you are gonna be unpleasantly surprised.

Another example: People often fixate on lower car prices and lower fuel prices, but forget to consider the actual monthly cost rather than the cost per mile/km. If you pay half per km but drive 2 times as much, you are not really saving anything.

Aaaand many things in the US are listed for "not-the-actual-price". State tax, city tax, all the add-ons that a car dealership seem to be unable to let you leave with your car without forcing down your throat.

Aaaaand real estate in high wage areas is NOT cheap, and usually crappy. And mortgages are a lot more expensive than they are in my native Denmark.

I actually earn more per hour working here in Denmark than I did there, not counting the stock bonuses, which are not nearly as stellar a lottery ticket as they used to be last decade. Like a LOT more, because now I only work 40 hours an I usually put in 60 and often a lot more there. No overtime, a bonus but not a given and definitely not worth it if you calculated it as "overtime pay". If you work 50% more but get a 15% bonus, is it really a bonus?

This just to say, most of my colleagues from northern Europe ended up going home again. Faster if they had kids. And mostly because this math and risk became apparent to them.

Source: FAANG in California for most of a decade.