The fact that inflation harms savings is simple elementary-school-level math. And since the real health of an economy is measured largely by production capacity + savings, any harm to savings is relative harm to the economy.
Savings are government deficit. For the non-government sector to save there has to be a surplus. For the non government sector to have a surplus the public sector must run a deficit. Every dollar in existence was issued through a deficit. Money is created out of nothing because that's the only way it can be created, but the government is almost always the last step in the process.
And the obsession with inflation is pretty weird. Eco-metrics don't suffer. Numbers don't feel pain or starve to death.
A real threat to sentient beings is from things like unemployment, social immobility, lack of education or healthcare. These are real social problems with real effects that are for more of a threat than the inflation boogy-man. The government issues currency mostly IN RESPONSE TO the non-government sector issuing debt. That debt HAS TO BE issued in order to fund savings and investment, which HAS TO happen in order for new jobs to be funded. Refusing simply stops new employment from being funded. These real social problems cause the economy to become deficient, reducing the usefulness of the economies sovereign currency, causing the government, when it HAS TO issue new currency to issue more and more as a simple reflection of the failing value of the currency caused by real social problems.
The US can never be forced to default on a debt denominated in dollars. It just isn't possible. It can't even be forced to pay interest to foreign holders of debt. Governments pay interest to purely control interest rates. And dollars can only be spent in the US, so all add to aggregate demand for US products. If the debt is denominated in gold, it can default if it can't get enough gold.