We have reached a point where it is virtually impossible for any resident of the USA to be totally innocent of every kind of crime because there are many thousands of crimes at every level of government and no one can be sure they have never violated any of them. The USA has become a country where those who work and save are not allowed to keep most of what they have earned. Those who are thinking of leaving the USA for more hospitable countries will want to have some assets offshore before they are ready to take that step. Perhaps the best reason to have some assets offshore is the possibility that the USA will establish currency controls and will prohibit citizens from taking any assets out of the country. If that were to happen, few other countries will want you because they won't want to pay for your care.
Affluent refuges are always more welcome than indigent ones .
Even if there never is a good enough reason to want to leave the USA, there is peace of mind in knowing that you can if it ever becomes necessary. While there are an abundance of investment opportunities in the USA, they are not necessarily the best investments for every investor. Some of the top mutual fund managers in the world have formed investment funds outside the USA that are not available to the US investor. Many of these foreign funds are even managed by US fund managers. The alternative is a risk avoidance method of investing.