There is indeed a possibility that a govt could, theoretically, borrow indefinitely. There is a LOT of assumptions in that calculation though, and it's pretty obvious the USA and almost every government never bothers to even try to live in that range.
So while what you say is theoretically possible, it's practically impossible, as there is almost no incentives for any people currently in government to try and sustain that, and incentives absolutely matter.
If you know of a practical example of this theoretical indefinite borrowing, I'd be very, very surprised.