Moreover, the “return to normal” at the global level looks like being a very, very slow process. And normal is a different place now. As would be clear from my utterances over the past couple of years, I have serious reservations about the extent of reliance on monetary policy around the world.
It isn't that the central banks were wrong to do what they could, it is that what they could do was not enough, and never could be enough, fully to restore demand after a period of recession associated with a very substantial debt build-up.