DAI is tied directly to the dollar. In what way is it better than a simple bank account for storing value? The idea behind gold, silver, property, etc as value

DAI is tied directly to the dollar. In what way is it better than a simple bank account for storing value? The idea behind gold, silver, property, etc as value stores is that they remain valuable regardless of what the currency does. If your value store is the currency itself you might as well just hold the currency.