Original records can be manipulated and falsified by officials or black-market forgers. It is also not difficult in most cases to create realistic looking replicas of official documents which contain false information.
The major challenge is that a paper-based document is used to transmit some kind of information and identity to the bearer. Because these documents are easy to forge or can be based on real, but stolen documents, they convey significant privileges to the bearer with only a small risk of exposure.
In a blockchain-based system, paper-based documents are replaced with digital documents on an immutable ledger. The immutable nature of the blockchain means that these digital documents are impossible to duplicate or forge because there is only a unique, single record.