Starting in the 1980s there was a concerted effort to eradicate bearer assets from the world. In a combined effort from FATF, the global anti-money laundering organization, and the US government, an agenda was pursued where all assets would become registered instruments. This would ensure that the owners of all assets could be known, taxed and tracked.
The problems for governments are fairly obvious. Assets that you can hold privately and anonymously are difficult to tax. Transfers that can occur between two people without any authority being notified can be used to launder money or evade capital controls.
There’s also the issue of counterfeiting. In 2009, over $130 billion in US government bearer bonds were uncovered by Italian customs officials. Without a central register modern printing techniques had made bearer instruments far too easy to counterfeit.