very old
Obviously it’s subjective but Debian doesn’t use ancient software. For instance Bookworm has Python 3.11; the current Python is 3.12. Some software updates slowly enough that you end up with the latest version. I seem to recall zsh being up to date. But yeah, make sure you’re using the correct version when looking up docs.
This is exactly why you need something like dbus. If you just have a socket, you know nothing about how the data is structured, what the communication protocol is, etc. dbus defines all this.