“Modern Monetary Theory (MMT) is a heterodox macroeconomic framework that says monetarily sovereign countries like the U.S., U.K., Japan and Canada are not operationally constrained by revenues when it comes to federal government spending. In other words, such governments do not need taxes or borrowing for spending since they can print as much as they need and are the monopoly issuers of the currency.” Investopedia
Of course governments are not ‘constrained’ by revenues. They have always been able to “print as much as they need”.
Modern Monetary Theory is not ‘modern’. Far from it.