I’m not arguing the point, but liquidity and cash flow are just as important. If I have a $100,000 appreciating but illiquid asset and owe $80,000 on it, it’s not to worry unless my cash flow is inadequate to service the debt. The total assets of a nation tell one nothing about cash flow or liquidity. We can’t raise money by selling Kansas.
I don’t know about the rest of the world but it seems to me our "free cash flow’ as a country gets smaller all the time because of unchangeable commitments of cash to things like SS and Medicare (and for all practical purposes the various welfare programs). And, of course, the debt service gets bigger all the time and would take an enormous jump if worldwide interest rates went up significantly.