Please read and re-read what I'm about to write until it makes sense, it's important. Sometimes cash is king. The reason it APPEARED that everything lost half of its price was because CASH was becoming more valuable to people and those other instruments are priced IN CASH. It's REALLY important to understand that. It doesn't mean MSFT stock was actually worth less, or that bonds stopped paying coupons, or that ferrari cars were suddenly ugly ... it just means that everyone was scrambling for cash and so they drove up THE PRICE OF CASH. Since everything is priced in cash, it APPEARED that those things were falling in price. In 2008/2009 there was an enormous destruction of money. Short term bonds, corporate debt, derivatives, etc, are all a kind of money, even if they aren't "U.S. Dollars", people treat them as such. When trust was being destroyed between parties in 2008/2009 money was being destroyed, and that put a premium on money, so everything denominated in U.S. appeared to fall in value. Just like people can scramble to purchase Tesla stock, or gold/silver, they can sometimes scramble to buy cash, and that will drive the price of cash sky high because they are willing to sell everything else .. the ferrari, Tesla stocks, bonds, or whatever it takes to get cash. You can usually tell when this is happening because everything priced in cash falls at once. You said "does nothing but cold hard cash survive .." during such times, cash doesn't just survive, its THRIVING. Sometimes he who panics first panics best ... and at such times buy cash before everyone else does ... then, just as any other long trade .. get out of it when the time is right. That means buying the ferarri, Tesla stock, bonds, etc, when nobody else wants them, trading them your expensive cash for their cheap stuff. Like everything else ... buy cash when it is cheap, sell it when it is expensive.
Some are touting gold as the asset to have in the next crash. However....gold lost ~33% in the 2008-9 decline, gold miners lost ~66%.
In 2008 my wife and I walked into our old bank (that was ready to go under). We withdrew all our money from it...Checking, savings, safe deposit box. We drove it over to Wells Fargo. Got diddle squat for our money...Maybe .2%. Safety first for us. Our old bank went under...We didn't know what would happen to our safe deposit box, but we wanted it at the safest place we could find. We had a lot of money on the side lines. We waited then added to our stocks. If I was younger I would have bought one or two rental houses...Newer homes, in quiet areas. In cities that are growing...Have a growing college. The city would have all the amenities a normal city would have...Hospital, choices of dentists, boring and safe (think of kids running in neighborhoods). But I had heart issues, so I didn't want to burden my wife with a headache. But if 2007-2009 happened again, I would encourage a younger person with cash to go that route. A 1200-1400sq ft house...At least 3 bedroom 2 bath...Easy maintain yard...No pool. That house is always in demand...Good times and bad. The only stock that did OK for me was RVT. It dropped maybe 40%...Close to what the market did. But it still paid out a 5-6% dividend. They find boring, stable, undervalued companies that have a good space in their markets.