Real assets aren't inherently more valuable than digital ones. I've spent much more on digital assets in my life than on physical assets. Cosmetics in video games are much more valuable to me than like clothes in real life. To me buying physical stuff is mostly a waste of money.
The USA army could be dissolved and the economy could switch to use something else. Of course these events have a low probability of happening but if someone wants to say something else doesn't have a floor because demand could dry up you can't say something else does have a floor even though demand could dry up just the same.