that doesnt mean bitcoin  is the only money.. 
It isnt.. 
Forms of money will always come around.. 
Economy is not a closed system, FIAT may die and will appear again and again. 
Debt is a tool
If bitcoin is the only money, debt will still exist. 



The only possible end for an "economy" based on debt is bankrupcy. The only reason it hasn't happened to the $ or the € yet is because they are the biggest. But almost everything bellow them have experienced bankrupcy and all the drama behind it. But the time will come that the $ and the € will also bankrupt. It's really unavoidable.