The entire purpose of QE and similar schemes is to reduce the value of the fiat currency relative to other things, in order to encourage people to swap their dollars for things (increasing consumption) or financial assets (increasing investment, at least indirectly).
The problem is that the investment doesn't seem to be happening, partly because of expectations of a future crash. By this point I suspect this has more to do with real-world factors (climate change is a serious obstacle to long-term economic growth) than government policy.
If we look back half a century in the US, the commodity held was gold. Or rather, federal reserve notes redeemable for gold.
Gold makes a good currency as it has the properties of a commodity that makes a good currency. It is durable, divisible, uniform, and portable.
Federal reserve notes a half century ago were even more portable. You could mark the bills or write down serial numbers and make the bills difficult to use if stolen. If torn, the Federal Reserve would issue you new bills.
Money or currency historically has been a commodity that had the above mentioned properties (durable, divisible, uniform, portable), so that it is convenient for trade. Really any commodity could be held to store value, although some store value worse than others (perishable food is not exactly durable).
When you get into very large sums which you may want to transfer around the world in a split second, you run into more of a problem of course.
People avoid holding money by buying stocks and housing, not because of natural P/E ratio but forced by the continuously devaluation of cash.
What "money" do you expect businesses want to hold in this situation?