For example the Roth IRA, will in most cases due to reciprocal tax treaties, allow for a tax free pension even when your tax residency is in another county.
On top of the trust structures I've alluded to, there are few reciprocal data sharing arrangements with countries forced to comply with FATCA. In other words, the data sharing usually only goes one way.
Yes, this is a remarkable pain to learn and administer, but it's all possible to do without paying thousands in ongoing accountant and lawyer fees.
This means that it's possible to shelter your assets in a remarkably secretive way the US. So in one sense, you could consider US taxes as insurance against spurious lawsuits in say the EU, or bad faith spouses wherever you get married.