In my country during the year 2016, 8th November the government announced currencies with highest denomination like 1000₹ and 500₹ won't be valued anymore. People are supposed to reach the banks and exchange it to any other denomination. In the event of this people suffered much, because there is no money to spend and banks were full of crowd. More than 100 lost their live standing in queue.
Whats the reason for such an immediate decision ?
The government stated it a reason to fight illegal funding to terrorism and recove the black money.
If there is validity or expiry for every currency same as day to day life needs, then people will make use of it and exchange to new currencies at the right time. This way everything can be made to be in circulation rather than getting accumulated for years. Here black money can also be avoided.
I remember that time actually, it really wasn't that long ago. The way it was just suddenly announced overnight also was quite reckless from the government. I understood it completely, because money launderers and black market illicit activities all keep their stash in thousands of these bills so the government wanted to smoke them out with no grace period. But poor people suffered in the end.