That's not what you're competing with. Your competing with a drivers license with a photo (not a great photo) and some countries have pretty easily faked drivers licenses, but others have drivers licenses in hard plastic with holographic features.
The credit card doesn't work as age verification.
We're talking about the EU here, where the standard form of ID is an ID card with very strict requirements, including multiple secure features and an NFC chip with the photo and some other information.
You're competing with photos of a drivers license.