Apple Pay is also designed to protect your personal information. Apple doesn’t store or have access to the original credit, debit, or prepaid card numbers that you use with Apple Pay. And when you use Apple Pay with credit, debit, or prepaid cards, Apple doesn’t retain any transaction information that can be tied back to you. Your transactions stay between you, the merchant or developer, and your bank or card issuer.
That sounds to me as if they collect everything they can and then anonymize it. So like with everything Apple you just have to trust them. If that’s enough for you, go ahead and use ApplePay.