Nation of immigrants? So are Canada and Australia, not to mention Germany and the UK at this point, and none of those countries work as long as the US on average.
Why the hell should GDP be the measure of the worth of a country anyway? As far as inflation and investments — it’s at best neutral. If value of money goes down 10%, value of investment goes “up” by a commensurate amount, you still end up with the same amount of money.
Good investments pay dividends, and that’s where the focus should be.