2016 is not 1933—there will be no confiscation of gold if there were to be a collapse. The country was on the gold standard at the time, which is obviously not the case today.

Both bitcoin and gold would skyrocket in the case of a USD collapse, which is unlikely, since the USD is the reserve currency of the entire world. If USD collapses that means every other fiat currency is literally worthless, so people would naturally turn to the dollar, boosting its value.

The problem with bitcoin is that 70% of the hashing power is located in China, so if something serious goes down, China isn't going to go out of its way to help us, so keeping the miners going to process bitcoin transactions isn't going to be at the top of their list.

Hopefully ethereum will be on proof-of-stake by the time such a collapse happens, so there would be no more need for mining and people can use their smartphones and laptops and not data centers to support a cryptocurrency.