And, considering the pilot is a safety critical part of the system, the same applies to number of flight crew.
Well, if you ask me I wouldn't enter an airliner without 2 old school pilots in the seats 0a and 0b but I am afraid that in the viewpoint of beancounters a future single pilot would be considered just as a back up
per se.
But my main point is that even if it would be technologically feasible the hardest aspect would be making such a solution desirable by general public.
Just because something can be done doesn't mean it should be done...