Thats true that some of the cases can be covered by 3D PDF, but there are others that require real size 3D models which user can walk around and check (for instance for quality assurance on site purposes).
Why does it bother you? What are you trying to achieve by keeping the models inside the devices, internal servers? This way you're loosing online collaboration possibilities, and most popular cloud providers like Amazon provide almost 100% of uptime which most likely can't be achieved using internal servers.
Again this depends on the use case, but most of them can be covered by a mobile companion apps (if we're talking about hololens app as a main app) and everybody have mobile phones nowadays.
How are you currently using 3D PDF?