You can absolutely live without a desktop phone... But you need a desktop PC to make it reliable. You simply cannot do VoIP calling from a "virtual workstation" scenario (unless you over-engineer that virtual workstation solution, which likely exceeds by an order of magnitude the money saved by "not having desk phones,") per the best practices of most vendors offering the solution. It doesn't matter if you have Lync or Cisco Unity, VoIP traffic is very time sensitive and the virtual workstations with application-based VoIP calling simply don't scale. You can carry off doing it with a couple instances, but scaling it requires significantly more network resources and engineering than you would have spent buying phones.

You can have a "virtual workstation" with a desk phone, or you can have a PC and "no-phone" but the technology does not work yet to have BOTH a virtual workstation AND not have a phone.... Which is what the article is talking about: A "no phone/no PC" world. There are still some tweaks and advances that need to happen before that becomes a scalable solution.