The working narrative is that these will, once again, renew global growth and allow governments, corporations and consumers to go even more deeply into debt.
No smart money takes out debts to expand to service new customers if the customers don't exist due to peak, 1st world, population demographics. And you can't expand forever on a finite planet so it had to happen at some point. Flooding the country with 3rd world invader baboons that aren't even capable of building or living in a 1st world civilization is the equivalent of trying to power your car by putting bananas in the gas tank.
Since it's not possible to nigger rig an infinite growth paradigm out of thin air, the debt based currency system that requires infinite growth to exist implodes in massive deflation. Instead of the banks ceasing to exist from all their loans going bad, the govt just hands them free money to bail them out and keep their balance sheet at non-implosion levels. The real economy numerical values are still experiencing stagflation or deflation, but the bank bailouts prevents asset prices from deflating to where they should go so nobody can actually afford anything.
Since there's a wage + asset price mismatch, the system and banks then just implode all over again seeking it's previous, natural trajectory of deflation. People noticed that bailing out banks does absolutely nothing without giving free money to the general population spenders as well to make both parties move in the same direction at once, so now they want to do that. But giving people free money makes them less productive (assuming the money maintains any actual purchasing power), which then causes the number of goods to decrease making it a seller's market and causing rise in asset prices possibly to hyperinflation levels.
Anything related to Keynesianism is a dysfunctional joke of unintended consequences and it will all eventually implode in some manner no matter what you do. There's a reason the coinage act of 1792 states the penalty for debasing the currency is death. As for Bitcoin, the amount of coins lost per year would always be enormous due to things like strong encryption and death, so all loans denominated in Bitcoin would go bad and you'd have the same deflationary armageddon collapse as the paper fiat situation above, while most physical metals are recovered. With the exception the bankers have rigged the price of silver too low that causes too much of it to be wasted in applications it shouldn't be and none of it recycled. The drop in supply will just cause price to skyrocket back to where it should be (several hundred in purchasing power) where it's not wasted and is recycled more like gold.
And no, you cannot force a 'gold only' monetary system like FOA claims and artificially prevent the monetization, price rising, and people using both silver and copper as well. You have extreme problems with lack of granularity and counterparty risk in a gold only system. It would never happen. After the fiat system implodes, people will demand ability to remove counterparty risk and are not going to use some crap like Peter Schiff and George Soros' "Goldmoney" to add granularity to gold by letting them hold it for you and inadvertently be forced into a digital only system. When metals are used, it's always going to be gold, silver, and copper all at the same time.