why further qe is unlikely, page-46

1.Central banks in most developed nations are institutionally designed to be independent from political interference.

Therefore you are incorrect in your assumption that Governments are buying.

2.The US dollar was given World dominance soon after the end of the Second World War. Bretton Woods.
USA is a far cry from those day in respect to its finances and has much abused its position, so much so it could very well collapse in the future.

I am sure you know all this timber.