Modern Monetary Theory (MMT) has been taking quite a drubbing lately. Some say it has been thoroughly discredited since it was de facto practiced (to an extent) during the pandemic, and massive inflation resulted. But that glib commentary misses the real root cause of the inflation: the shortages of goods, services, and labor resulting from the massive global supply chain disruptions, which in turn resulted from the lockdowns and related restrictions.
(And it's not entirely due to ignorance, since those naysayers actually DO admit as much about the lockdowns, but yet they still speciously put most, if not all, of the blame on MMT, because reasons.)
MMT per se was never the problem. But to refurbish it, one must admit that lockdowns and related restrictions did very real harm, something that the pseudo-left is loath to do. Not that MMT is flawless, by any means. But Rodger Malcolm Mitchell's related theory, Monetary Sovereignty (MS), essentially fixes those flaws, especially when he (belatedly) jettisoned the specious idea of interest rate hikes (which only deepened the stagflationary quagmire) as an inflation-fighting tool. A good essay about the differences between the two can be found here.
In a nutshell, when you literally shut down the broader economy in most of the world for an extended period of time (which greatly disrupts and shrinks supply), AND then try to paper over it by printing unprecedented amounts of money (which stokes demand), that WILL be inflationary. But the money printing was NOT the root cause, and remember that if the powers that be didn't do that, there would have been a full-blown depression, if not a complete collapse of civilization as we knew it, and within a couple weeks the masses would have been furiously calling for their heads with torches and pitchforks. Or, they could have simply adopted the "flu strategy" and NOT imposed any restrictions, and perhaps implemented a more modest (but more brief and front-loaded) stimulus package, and this whole stagflationary quagmire could have been avoided. And as the experience of Sweden and other countries has famously shown, it would not have resulted in any more excess deaths than occurred with lockdowns. Hindsight is quite literally 2020.
It's not that lunch cannot ever be free. It actually can be, at least to a point. But truly lockdowns can never be a free lunch, no matter how much money gets printed to paper over the massive holes they make.
As for the specious notion that MMT (and by extension, MS) is a "luxury belief", well, we know that the real luxury beliefs are austerity and artificial scarcity. Not to mention lockdowns as well.