The $60'000 cap for US investments

Yes, the global net worth needs to be below the limit to be fully exempt from estate taxes. As of 2023, the threshold is USD 12.92 million for individuals, double for married couples, though, so this is probably not a concern for most people. That said, there is a chance the exemption will be lowered in the future.

There is some discussion on this towards the end of this thread: Are US ETFs worth the (estate tax) troubles?