I don't think the US (as a nation) will ever pay of its debt. Its citizens might pay off their own debts, but the perpetual desires of capitalists for line and number to go up is not compatible with the physical environment in which we find ourselves.
It is unrealistic and perpetual growth is not possible, nor should it be an incentive.
There is such things as having "enough", and "enough" is abundance.
I can only drive one car at a time.
I can only be at one place at a single time.
I can only eat one ice cream cone (reasonably) at a single time.
But a symbol of excess, I don't want to do the mind-math of "how many cigars can a rich man shove in their mouth at a single time?" I imagine its more than one. I don't even know what a cigar costs.
But having multiple yachts? Capsize, you fucks :P