[knorker]

> The only thing that maintains the value of any asset (or currency) is the collective belief in that asset or currency

That simplifies too much. There's also the fact that all taxes on income, capital gains, and consumption must be paid in this currency.

It has a very real value, in that if you don't pay using this then people will come and lock you in a cell.

It's not just a collected belief.

I also believe that the government will by force not allow its own currency to be replaced within its borders.

That's a belief in a trusted third party, not a collective belief.