The combination of extremely low and relatively stable US government bond yields has confounded many market watchers for quite a while now, also challenging traditional economic analyses.
One should never underestimate the power of central banks intervening in market pricing.
After all, what is more assuring than a central bank with a fully-functioning printing press willing and able to buy assets at non-commercial levels.
... possibility of collateral damage and unintended consequences.
Mohamed A. El-Erian FT 29 September 2021