In a previous post, it was explained that enforcement of taxes (or some other financial obligation to the state) that can only be extinguished (i.e. finally settled) with money issued by the government is fundamental to the viability of a national currency. Without such an obligation, widespread acceptance of the currency would not be assured. The currency might cease to serve as an effective mechanism for public provision of adequate infrastructure, education, health care, social security and much more.
It seems to me that those, including New Keynesians, who support the maintenance of a “balanced budget over the cycle” are either not recognizing or rejecting a number of points made by heterodox Keynesian (or Kaleckian) critics of such a policy approach, including proponents of Modern Monetary Theory (MMT) as well as many other Post Keynesian and Sraffian economists.