Honest question: why use this and not FaceTime?
The two mains reason right now would be because you can do screensharing and because this is not tied to your iCloud account in any way. In the future, we will probalby have other clients other than the macOS one.
Does anyone with a Mac not have an iMessage account, leaving their texts green instead of blue? That audience seems small.
To keep work separate from personal, I originate work texts and FaceTime from the work # on my dual number iPhone. This is also settable per Contact.