If you use a modern Linux system with KDE, you can try removing PA. Odds are you won't notice that it is gone. Not saying that network audio is a bad feature per se, but in my ten years of using PA, I have never needed it. IMO, systemd and Avahi are fundamentally different from PA in that most users have no need for the latter but almost everyone for the former.
Because KDE has Phonon, an audio subsystem way more complex than PulseAudio (and in my experience, more bugged too).
Things like hotplug, Bluetooth devices and as such shouldn't be managed by your desktop manager, unless you want for things like hotplug and Bluetooth to only work in KDE.
Phonon is only an abstraction layer with API and ABI guarantees so every time a new technology comes and goes, all app developers wouldn't have to port their existing codebases.
Funny story:
During KDE 4.0 development, KDE introduced Solid library. Which abstracted HAL.
HAL was Linux'es "Hardware Abstraction Layer".
So HAL developers mocked KDE and got some tshirts that said "KDE Abstracted my abstraction layer".
1-2 years later HAL was deprecated. And Solid got a new upower/udev backend and no KDE developer had to port away their code from HAL to anything else.
Phonon's situation is similar. Xine, gstream, vlc, these technologies come and go. KDE apps don't care.
Also Phonon can get a QuickTime backend when it's built for Mac or something else for Windows.
