The debt cannot be paid off because retiring debt destroys money is our current system. If the $35T in debt was paid off, there would be literally no money left in circulation.....as in a .01 penny would have staggeringly insane purchasing power.

Secondly, selling BTC would be a really ineffective way to manage the debt....(once its sold your trick is done).

They will do what what MSTR currently does (and what most companies will do), Bitcoin will become a Balance Sheet asset and higher bitcoin prices will enable higher debt levels. (ie. $4M bitcoin price X 1M BTC = $4T balance sheet asset so that could be leveraged up to say 40-200T additional currency issuance/debt).

This is how Gold was supposed to function to Fed Reserve, but congress / great depression derailed that....