ID cards will never prove identity.
How do you apply for an ID card? "Bonjour. Je suis Monsuir Jo Bloggs. J'arrive en Englais. Je voudrais un carte d' ID. Ici mon Passport Francais." Is a French (or Italian or Polish or Romanian) passport good enough? If not, how does someone prove their identity? If so, then the ID card system is as strong as the most corrupt and incompetent passport office in Europe. Not to mention the possibility that the underpaid spotty youth on work experience behind the counter is on the take.