The insight of modern monetary theory is that rule does not apply to government, when debt is in the money issued by that government.

Yes that was one of the arguments I've seen. Feels good! doesn't it. It's wrong, though.

It can be rolled over indefinitely, by issuing more bonds.

Of course it can! Lenders will lend, lend, lend to governments because they know they will get their interest payments.

But the taxpayer is paying, paying, paying interest. When the interest bill rises to 10% or more of Gross Domestic Product, that payment becomes a genuine drag on the economy. Loans are not free. They have a cost. MMT pretends there is no cost. It's bullshit.

Just to show that none of this is new, that the bullshit is old and that people were seeing through the bullshit even then, here is an excerpt from 1983. The source is not important but I'm happy to give it if asked.

"Economists, and those controlling money, have persuaded people and their governments that development necessarily involves the creation of monetary debt. So most development is carried out with loan money, rather than out of income. The result is a piling up of debts, the interest on which, alone, is crippling many nations, while amortisation becomes a rapidly receding possibility, achievable only by inflationary decrease in the real value of the money borrowed. So great have many international debts become that nations are becoming bankrupt, with inflation rates of 100 percent or more. The barter system of the world, through money, is in danger of complete collapse, rather as happened in Germany after World War I. With governments as with individuals, there is something fundamentally unsound about spending much more than income, for it is impossible to be absolutely sure that a development will generate the expected increase in income."