Having spare cash around is never a bad idea. But there are precious few timelines in which the banking system collapses so completely that savings are inaccessible for extended periods (or at all) but paper U.S. dollars continue to hold value.

If you want to have a reserve for a case when things go badly wrong, banks all go under, government can't bail them out, etc, then park some of your cash in yuan and rupee, in a piece of overseas realty, in gold bullion, and don't forget to invest in medical supplies, shells, and other such gear.

Different views of the future risks drive different decisions.

Inflation is a constant.

(And to pre-add, precious metals haven't historically been a great hedge either, when benchmarked against investing in economic growth)