Because the world has an anemic shortage of dollars. The reason for that is post 2008 banks have become much more risk averse (seeing what happened to Lehman e

Because the world has an anemic shortage of dollars. The reason for that is post 2008 banks have become much more risk averse (seeing what happened to Lehman et al) and they are mostly the conduit through which broad currency is generated. That mechanism is mostly broken unless you’re an ultra rich company like Apple or Google. So today to make a bank create USD for you you’d be required to have the best of the best collateral namely sovereign bonds. As it stands the US hasn’t taken even close to enough debt and thus issued Treasuries to even come close to the shortage in dollars that banks’ risk aversion has created since 2008.