Answer:
It helps improve their credit history and it helps them be able to get one in the future without the hastle.
Step-by-step explanation:
The reason why it would help their credit history is becasue if they dont intend on using it then they wont be spending money that they dont have so then they wont have to pay it off every month. And getting a creditcard in the first place is pretty difficult becasue they always look at your credit score or history and most of the time when somone applies for a crditcard they dont have a creditscore or history.