>Dismissed by some as Monopoly or plastic money, the new £5 and £10 notes in particular have come in for heavy criticism.

It's a common metaphor, but it's just a simpleminded metaphor. The US Treasury printing has literally nothing to do with inflation (if it's printing adequate amounts of replacement bills). No US government account is paid with fresh bills, hot from the Treasury presses. Those unwrinkled notes are sent to replace damaged bills returned from banks at a strict 1:1 rate.

Instead, money is created by issuing bonds (via the interest paid). The possibility of creating inflation is still present, but no printing presses are involved (Treasury nor otherwise).