Risk analysis
Soyuz / ISS rendezvous has now been fully automated to give a 4-orbit ascent and docking in under 6 hours. Ops efficiencies will drive implementation of automation in air flight too resulting in piecemeal introductions - easiest and greatest savings first for commercial contexts. A similar time-line will evolve for the military with differing concepts of what constitutes a saving. Once in that future the greatest threat to air safety becomes each still-human-operated rig which might decide to not co-operate with the global airborne separation system (GASS). Following risk analysis and agreements with unions crew in the pointy-bit will be retired from service and everyone in the air will feel much safer knowing they're not going to have a couple of human-beings being human at inappropriate moments (eg, caught up in a discussion about company policy and cruising on past the airport while GASS directs everything over, under and around them).