The banks are not hoarding cash they are loaning it all to government. Buying bonds. Then borrowing more from the federal reserve at .25% and buying bonds at 3%.
There is a wild man in charge and this is the safest bet they could find.
Plus they know they can always be punished by the Dems if they don’t buy the bonds.
The Democrats can use whatever crises comes from their policies to get even more power for themselves.