Do a charge back and experience it yourself...you can’t just “use a different card”

Ever occur to you that someone using a debit card may not be able to "just use a different card"?

Perhaps this is an America-centric point of view, but almost everyone has multiple cards.

You can also use a prepaid credit or cash gift card to create an account or pay for Apple content.

Perhaps this US centrism colors Apple's view as well?

You don’t need a card to keep using the apps you’ve purchased.

You don’t need a card to maintain or get an Apple ID (unlike implied bythe default user flow, it’s possible to get w/o one).

You don’t need a card on an Apple ID to download free apps.

You even don’t need a card on an old account to use apps from that old account on the same device as apps from a new account, you just need to be able to provide valid credentials for both (seems like triggers when the device is trying to update the apps in question).

Almost everyone of a certain level of means has multiple cards. If you only associate with people around your economic level, it is easy to believe that everyone has multiple cards. I have many friends in NYC with only a single debit card and either no credit cards (due to no or poor credit) or a few credit cards that are all maxed out.

It's also worth noting that many companies with subscription services specifically block signing up with gift cards. I do not know if this would apply to Google Pay or not.

You don’t need a card of any sort to pay for stuff in Apple’s ecosystem.

iTunes gift cards are readily available at common retail outlets, which take cash, and can be used for apps, iCloud, and the rest of it.

Sucks that GP got his debit card blacklisted, that would annoy me as well, but “bricked”? c’mon.