It gets recycled and increased. That is no reason to believe it can continue ongoing.

Modern Monetary Theory (aka Neo-Chartalism) is a reason to believe it can probably keep on going.

I ended up staying in tech instead of pursuing doctoral studies in Economics, but had life broken a different direction my thesis would have been (loosely speaking) related to assessing how governments could leverage MMT differently depending on whether or not they're an issuer of one of the common global reserve currencies.

I was ultimately turned onto the underlying theories after breaking from Neo-Keynesian theories in the wake of QE1 & QE2, but before QE3 was in full swing.

MMT assumes a sovereign can never default. That is not a politically realistic. At a certain debt level, American politicians would default. That ignored threshold, in turn, makes MMT’s suggestions dangerous.

I don't think it has much to do with politicians. It has to do with currency counterparties and economic value created therein. Hence my desire to study where I think MMT can make the biggest net impact. Which is likely in currency issuers who are Too Big To Default™.

All money is just an agreed upon fiction by multiple counterparties, and when there's a lot invested in that fiction it becomes fairly undesirable to be the one(s) to pierce the suspension of disbelief.

It's been going since the days of FDR. Whilst I don't claim it will go on forever, the US is in a mich better position to do thos than any other country so it's hard not to.