Parent and GP are using different definitions of "dollar."
GP is using a strict definition (only dollar-denominated liability of the Fed is a "true" dollar), parent is using a looser definition (a dollar-denominated liability of any bank is a dollar).
If you have a fractional reserve (e.g., a bank has $100M cash backing $100M deposits one day, then loans out $30M the next day), with the strict definition you still have $100M dollars ($70M controlled by the bank, $30M that was loaned out and used to purchase stuff). But with the loose definition you have $130M ($30M is still loaned out, depositors are $70M).
Essentially the depositors have made $100M of (debt) investments in the bank, and those investments are now 70% backed by cash and 30% backed by paper (mortgages or other kinds of IOU's from whoever they loaned the $30M to).
GP is using a strict definition (only dollar-denominated liability of the Fed is a "true" dollar), parent is using a looser definition (a dollar-denominated liability of any bank is a dollar).
If you have a fractional reserve (e.g., a bank has $100M cash backing $100M deposits one day, then loans out $30M the next day), with the strict definition you still have $100M dollars ($70M controlled by the bank, $30M that was loaned out and used to purchase stuff). But with the loose definition you have $130M ($30M is still loaned out, depositors are $70M).
Essentially the depositors have made $100M of (debt) investments in the bank, and those investments are now 70% backed by cash and 30% backed by paper (mortgages or other kinds of IOU's from whoever they loaned the $30M to).