Except that you may not be able to because those can be banned by the government. For example, from 1933 to 1974 it was illegal for people in the US to hold gol

Except that you may not be able to because those can be banned by the government. For example, from 1933 to 1974 it was illegal for people in the US to hold gold because the government needed to raise money from its citizens. Holding gold doesn't help the government. And forget about getting your hands on US dollar. Of course the government can ban holding crypto, but that's going to much harder to enforce since it's just bits.