Good post by Contour Flyer
I am prepared to accept that at some time in the distant future 'anything' is possible - however for the immediate future (i.e. 200 years) pilotless airliners do not make safety, or commercial sense.
Some people here have suggested that also engineers could be replaced. I doubt that is likely ever. (well not in the next 400 years anyway!)
I speak as an ex LAE, ex Flight Engineer, Captain and General Builder.
Regards
Exeng