Congrats on missing my point.

  1. old situation: currency backed by full (gold) reserve
  2. actual political decision: currency no longer backed by full reserve
  3. result: currency no longer backed by full reserve

  1. possible political decision: return to currency backed by full (gold) reserve
  2. possible political decision: currency no longer backed by full reserve
  3. result: currency no longer backed by full reserve

To whatever extent government could return a full-reserve backed currency, government can move away from that again. Thus, there's no builtin security for anyone in a return to a full reserve backed currency.

If no government in the history of the world had ever done this, then arguing for a full-reserve backed currency might have a bit more weight. But they have, and it really has done.