Many things that came out of freedesktop.org are pure garbage. The most prominent example is dbus. Personally I hope they have no success in standardizing anything further.
There are many ways to do IPC on a unix system. Dbus is a reinvention of IPC in the worst possible way. It requires a daemon to run and it requires every client to be able to parse and generate JSON. The worst thing is that those JSON packets are not even human readable most of the time. Protocols that are running on top of that are also not standardized. If you are lucky KDE and GNOME agree on something. Many times they don't.
Except that it was designed to be read into memory and directly accessed without parsing. A GVariant Array has the form of its elements and their lengths. You can index into an Array in linear time.