Why do airlines share my itinerary with my bank? GDPR violation? Any travelers switching to cash?

cross-posted from: https://links.hackliberty.org/post/125466

My credit card issuer apparently never gets to know what I purchased at stores, cafes, & restaurants -- and rightfully so. The statement just shows the shop name, location, and amount.

Exceptionally, if I purchase airfare the bank statement discloses:

• airline who sold the ticket
• carrier
• passenger name
• ticket number
• city pairs

So that’s a disturbing over-share. In some cases the airline is a European flag carrier, so IIUC the GDPR applies, correct? Doesn’t this violate the data minimization principle?

Airlines no longer accept cash, which is also quite disturbing (and illegal in jurisdictions where legal tender must be accepted when presented for PoS transactions).

Has anyone switched to using a travel agent just to be able to pay cash for airfare?

UPDATE

A relatively convincing theory has been suggested in this other cross-posted community:

https://links.hackliberty.org/comment/414338

Apparently it’s because credit cards offer travel insurance & airlines have incentive to have another insurer involved. Would be useful if this were documented somewhere in a less refutable form.