Situational Awareness is a lot more than the PFD and ND.
Otherwise, I agree with you.
All the electronic monitoring in the world will not, for me, replace the benefit of another human brain in the cockpit. Computers are fantastic tools but are there only to aid the human.
In my ex-company the F/Es were an integral part of the flight crew and wholly included in managing the flight. I suspect that there are those who would make the same case for the Navigator as well and undoubtedly there are some CFIT accidents that would have been saved by the presence of one.
However, the accountants and bonus driven managers rule the world. Computers are cheaper than people, and the actuaries develop another spreadsheet which shows that the cost/benefit ratio favours paying for a few hull losses over paying for more crew.
Just because I'm cynical doesn't mean I may not be right.