you don’t even need a card to receive money on paypal. it goes to your “paypal balance” which is virtual money basically. it’s a credit from paypal. you can get that money removed onto your bank account if you ever want to, but most transactions from paypal, stay on paypal. You can pay with eitehr the paypal balance or a credit card however.
Scenario
Steve has a paypal and wants to receive money. he has his credit card on file but no bank account.
John sends steve 40$ through paypal from his credit card funding.
Steve receive 40$ into his paypal balance. the amount on his credit card/debit card stays unchanged.