Which really entrenches a specific philosophy of what the relationship should be between the state and the citizen.

A mandatory ID card says that every citizen has to prove their validity to the state, and it is the state which can grant or revoke that validity, rather than the state being the servant of the citizens.

There have surely been enough examples by now of successful countries not requiring mandatory ID cards, and examples of ID cards being abused by governments for discriminatory policies, that I don't know why they have such support.

http://www.preventgenocide.org/prevent/removing-facilitating...

https://privacyinternational.org/long-read/4472/exclusion-de...

https://bc.ctvnews.ca/99-of-indian-status-card-holders-have-...