"Austerity" is a red herring. I mean let's be serious, every option is austerity for someone...

Cutting spending, means those who would have received that debt spending take a loss (perhaps their job). Raising taxes means taxpayers pay. Raising productivity or inflating the debt means the young and laborers shoulder most of the burden. Financial repression means capital owners pay. Defaulting means bond holders pay.

This is what people who argue the debt doesn't matter don't understand. Sure it doesn't matter in the sense that we could always just roll the debt forward, and continue to make future generations pay. Just as it's possible to choose over and over again to wine and dine at someone else's expense, against their will.

No the debt always matters, because, it's a matter over who gets to benefit and who has to pay.