I understand that bitcoin is decentralised, but decentralised what? Currencies need to have an underlying useful asset or guarantee. Yes governments used to h

I understand that bitcoin is decentralised, but decentralised what? Currencies need to have an underlying useful asset or guarantee. Yes governments used to have gold backed currencies but our economic growth is exponential, so it is now the job of the state. Incase they act irresponsibly it does go into hyper inflation, so they are forced to act responsibly. In case they do print more, it does go into public good like roads & bridges which adds to the public assets and hence adds to the assets backing the currency.