To use a family sharing, each person must have their own Apple ID. You donāt have to share purchases if you donāt want to do so, but one person, the organizer, must be responsible for all payments and must have a credit card or debit card that can be used for payment. However, if each family members redeems their own iTunes gift cards, and as along as each member has a sufficient balance in the Apple ID from gift cards, the organizerās card will not be used for purchases. So in essence, each member can pay for their own purchases but only by using gift cards.
The iCloud storage must be paid by the family organizer but the organizer can also redeem gift cards to use for iCloud storage payments.
Even the kids can pay for their own purchases if they use gift cards, but you will still have to have a credit or debit card on file as a method of payment if you are the organizer.
My family has been using Family Sharing and we all redeem gift cards so my card (Iām the organizer) is never charged for any purchases or for the iCloud Storage.