The reason hard copies of most documents will exist for a long time -- building federated digital systems is a huge pain in the ass.
Sure, you can have a digital passport for purposes of authenticating yourself, which is operated by your national government. Will this government allow the same level of access to the embassy of North Korea or some other geopolitical adversary or just to a random sim card issuing shop in a mall oh the other side of the globe? Maybe they will in the same way corona certificates were implemented. Now will every single place that legitimately needs to have a copy of your id on file be bothered to interface with this system and all slightly incompatible versions of it provided by other governments? Probably not.
And passports are kinda sorta simple to begin with.
Sure, you can have a digital passport for purposes of authenticating yourself, which is operated by your national government. Will this government allow the same level of access to the embassy of North Korea or some other geopolitical adversary or just to a random sim card issuing shop in a mall oh the other side of the globe? Maybe they will in the same way corona certificates were implemented. Now will every single place that legitimately needs to have a copy of your id on file be bothered to interface with this system and all slightly incompatible versions of it provided by other governments? Probably not.
And passports are kinda sorta simple to begin with.