[hocuspocus]

Completely false. They don't apply to 3-party systems.

[MrDresden]

Not correct. I was there, inside a EEA region bank, as Amex was pulling out due to the fee structure coming online in 2018.

[hocuspocus]

Co-branded Amex cards essentially became considered no different than 4-party cards and stopped being exempted from the cap interchange in 2018. Nothing changed for Amex proper. How would you even define interchange when it's indistinguishable from the scheme fee?

There's a reason every European PSP charges 2-4x higher fees with Amex cards.