Just a matter of time. While not tomorrow, next year or in 10 or even 20 years to be fully autonomous - it’s definitely plausible to cut the crew down by one or more, half if you will. Long haul crew of 4 becomes 2 = 1 Monitors, 1 Rests. Granted international flying ain’t coming back anytime soon like it was before, but a 25% or more reduction of the pilot force is fairly significant and probably not that far off as one might believe. Plenty of single pilot operations on much smaller scales with no automation whatsoever have been going on for a long time.