The FAA establishes blanket regulations (1) for the greatest degree of air safety and (2) in order to clearly determine who is at fault in the event of an accident. They also make it clear that the PIC is responsible for his/her own actions and decisions that are made during any flight operation. Establishing a set of rules often requires turning a blind eye to reality in order to cast the widest safety net for society. I would bet the farm that every Part 107 pilot often takes his eye off the sky and looks at their screen to some degree when recording video or snapping photos for their commercial work. (If I'm wrong, then why does one even have a screen?) There are also times when the drone may periodically leave one's line of sight behind a tree or structure during the course of the work, and it doesn't help that the FAA does not allow a PIC to daisy chain VOs with hand-held radios. (Idiotic that they don't, IMO.) In my experience, reality always wins out over rules that are idealistic, and I just try to be as safe as possible when I run into that type of conflict. Why? Because I will be the one responsible if something goes terribly wrong.