Are You Being Charged For Unused iPhone App Subscriptions?

Nobody enjoys paying for subscriptions that you don't use, or even know that you have.
According to Business Insider, Apple CEO Tim Cook said "300 million Apple users are currently subscribed to either an app or an Apple subscription service, like Apple Music."
Cook mentioned this in 2017 during an invite-only meeting designed to convince developers to adopt subscription models.
But Business Insider says that there may be many iPhone app subscriptions that users are paying for but not using.