The Central Bank would need to sell that debt on the open market to quell inflation so it is still relevant. If the debt is high enough that it constrains the c

The Central Bank would need to sell that debt on the open market to quell inflation so it is still relevant. If the debt is high enough that it constrains the central banks ability to manage inflation without causing default either high inflation or massive private debt default are inevitable in the long run. The only “out” is a miraculous increase in future productivity or an increasing percentage of working age adults that increase GDP to make it sustainable. Of course in the long run we are all dead.