This was what stood out to me, too! And this:

Packfiles are the fundamental building block of Git storage and Git networking.

(emphasis mine)

His approach was storing the objects in a distributed hash table. This was only possible thanks to JGit, a custom Git implementation in Java. Like any good ol' Java library, JGit provides enough interfaces and factories and interface factories to abstract all the details of a normal Git repository, including replacing its on-disk packfiles with a DHT. Although the system worked and results were good enough for normal Git operations, the limitations of the Git protocol (which again, require packfiles to be sent over the network regardless of how you store data on the server) made the git clone performance bad enough to discard the design altogether.

Looks like Java enterprise design patterns aren't all bad after all :-) and the git ecosystem would have profited from a bit of abstraction and separation of concerns here, where network protocol, git domain model, and storage layer are evolved somewhat independently. The domain model is what everyone in the ecosystem needs to agree on, the network protocol is what at least the given local & remote host need to agree on, but storage is mainly a local concern.

Of course the question is whether git would have today's market and mind share if they had gone down that path. The ecosystem would be a lot more heterogeneous, evolving network protocol would probably take much longer, etc.