That guy is living in a total fantasy. If you are a hammer then everything is a nail, so he has replaced reality with his digital version of it and is in for a very hard reality check.

When the system crashes that means that the global network is down then overnight everything becomes purely local again. Food, energy, medical care etc. Back to the barter economy. Just like Cuba in 1990 and the USSR shortly after. I remember the Poles on the black market in Berlin. As a kid, in the '70, I lived through a short civil war in Africa. The logic is always the same.

So if the global economy were to crash, make sure you have something physical to trade. Food, energy, medicines, sex, drugs, weapons and protection. Bitcoin is for fools. Only their handlers get rich.