I've heard that phages have a narrow target. They are not broad spectrum like antibiotics. Most of the time you don't know they exact bacteria that is causing the infection and to figure out may take days.
This is the major problem, in my view, with phage. You cannot treat until you've not only diagnosed the infection, but tuned the phage library being used. That's slow, even at major hospitals, and a major problem in places where diagnostic availability is limited.
