You just moved the goal posts. Typically when a currency collapses it doesn't go to zero it hyper inflates. Your $2 coffee now costs $200 or $2000. In such a situation your $2 XYZ coin is now worth $200, $2000 etc.
Of course if the world goes full Mad Max all bets are off.
Crypto is valued in euros, pounds etc as well as the dollar.
Is a length of wood worth less because you measure it in meters rather than feet and inches?
You just moved the goal posts. Typically when a currency collapses it doesn't go to zero it hyper inflates. Your $2 coffee now costs $200 or $2000. In such a situation your $2 XYZ coin is now worth $200, $2000 etc.
Of course if the world goes full Mad Max all bets are off.