See https://www.cbo.gov/publication/56910
Debt as a % of GDP has been rising since 2000. Our ability to fund our government has been lacking every year since 2001, typically with a deficit each year between $500B and 1.5T a year. We are fortunate to have super low interest rates so that our net interest payments stay low while we spend an incredible amount of money we don't have. Part of the health of the economy now depends on excess government spending (which we can't raise enough revenue to fund). So when interest rates rise, which they will do in time, our net interest payments will rise as well.
While our net interest payments rise, our ability to cut government spending or raise taxes seems unlikely to be able to match it. Furthermore, your assertions that economic growth will cover the rise in interest payments does not seem to be a given to me. We have had solid economic growth over the last 20 years, however, our ability to fund our government spending has not changed at all. See the year after year deficits we always run.
CBO estimates that by the end of the decade, net interest payments will double compared to today, reflecting the thought that we are enjoying historically low rates currently: https://www.cbo.gov/publication/56542
>This is all actually making our system more fragile.
>Now that so many countries, led by the U.S., have massively increased their debt loads, if we got even a small burst of inflation that drove interest on the 10-year Treasury to 3 percent from 1 percent, the amount of money the U.S. would have to devote to debt servicing would be so enormous that little money might be left for discretionary spending on research, infrastructure or education — or another rainy day.
>Sure, we could then just print even more money, but that could threaten the status of the dollar as the world’s reserve currency and raise our borrowing costs even more.
The evidence suggests the system is stronger than ever. The US stock market and economy outperformed much of the rest of the developed and remerging world post-Covid in spite of a lot of deaths. It is not the absolute debt that matters so much, but rather the interest paid on debt relative to GDP, which is very low and has been falling for a long time. Rising interest rates does not mans that the debt will be harder to service, because the economy will also be growing more too. There is also huge demand for treasuries by pensions and sovereign funds, which should keep rates very low for a long time to come.