That's because forging the passport or ID card, or impersonating someone else with borrowed/stolen passport or ID card, are serious offenses that will land you in prison.
What's often forgotten when comparing digital and meatspace security is that "angry men with guns will come for you and put you in front of a judge" is a critical part of security systems in meatspace. The very possibility of it acts as a powerful deterrent for casual attacks. Governments can rely more on this than private companies, so at least in meatspace, you don't need to jump through as many authentication hoops as you need with banks.
(Digital is different, governments sometimes overdo the hoops there, because for any Internet-connected system the pool of would-be attackers consists mostly of people from outside the reach of law enforcement of the country that hosts the system.)
This sounds like governments and government 'officials' (ooh, you work for the government, now you are 'official') somehow automatically loose their jurisdiction somewhere between meatspace and cyberspace. They don't.
I mean, ask Kim Dotcom about angry men with guns. Don't ask him about the judges, I guess.
There was also a French government plan (there was an app in beta, i should take a look at it again) to validate user identity with a smartphone and conformant passport / ID card ( the recent ones with chips and NFC) - you use the app to read the biometric info from the passport / ID card, and then take a video of yourself which is then matched, thus confirming who you are.
It seems so simple to have a global standard for some government API with perhaps some [portable] card reader and perhaps some ISP logic. Nice developer tokens with permission levels that can be revoked?
Or is that [again] one more naive idea?