If you don't want kids.

If you do, it's always a factor. Do you want your kids to grow up in a stable culture, or in a declining one? Surrounded by polarization, extremes of all kinds, instability? I consider moving to the US for a couple of years for the money, but the second that kids are on the horizon, I would book a plane ticket to Europe.

I get that you may want to move here if you want to have kids, but isn't Europe declining at least as fast as the US?

European fertility levels are lower than the US, so they are declining faster.

Fertility rates are not the only factor in a declining society.

No

Depends what you mean by "have money". Plenty of small business owners with a few million dollars in savings and assets have had to liquidate them to pay for healthcare for themselves or their family members. It can cost over $1 million to survive a heart attack in the US, and the disability of oneself or family members can easily cost millions of dollars in healthcare expenses over a lifetime.

For that purpose 'having money' is not the kind of money that a typical immigrant from Europe will bring with them, especially not if they still have to work for a living.