More on the “Non-Need” for a Traditional Business Phone

So how about some more thought on what really is needed for this so-called "non-phone" phone?
Clearly, you need a reliable voice path. Plugging in a USB headset into your PC won’t cut it in many situations because if that CPU gets busy, you could start getting voice quality issues. So you need something with its own chipset dedicated to voice.
What else? A headset jack, POE, mute, volume control, and an emergency call button. That seems to be about it. Everything else can be driven from the PC on the desktop. Am I missing any functionality?
This device’s applicability seems more geared toward the contact center vs. the enterprise, but some forward thinking enterprise users might go for it as well.
So if you could get this device at a fraction of the cost of a standard desktop phone, multiply that by the number of users…this could be a substantial money saver. And deliver greater functionality through the software application. Seems to make sense.