This, but broadly speaking, the US is a different culture. There are many other small things that could get you, too. There are upsides for sure, but some downsides you might not think about other than those obvious ones.

US taxes are a pain. You absolutely need a car. 4 hour car journey are "short", coming from Europe it's sometimes hard to mentally grasp the size. Metro areas in the US are huge. Commutes in cities where you would get the highest salary can be insane. They have little green space, and what is there and easily accessible will be packed on weekends. Broadband is hit or miss. Worrying about healthcare. The cost of university for kids. Being salaried can mean loads of overtime or uncompensated on-call. Depending on the state, ridiculous non-competes and "everything you do in your spare time is also ours" clauses. Visas and an insane path to permanent residency should you want to stay. Everything is non-metric.

You shouldn't move just for the money. Happiness is a hard thing, and the grass is always greener on the other side.

Edit: Apologies, OP said "work for an American company from Europe" - I think this will be hard, especially trying to demand a US salary without moving, but good luck if you can do it.

and in a big city, rent + food will cost way more

and if you have kids, you might need to pay for childcare and maybe even their education

Having 6 weeks off is a good start.

How much do FAANGs in the US give?