A nice thought, but we're not ready yet. We need the warning, navigation and communication systems in place first. TCAS is inhibited at low altitudes, so we're relying on looking out (human) and ATC radar (human/communication) Radars can fail. ATC can screw up. Communication can be lost. GPS can be jammed or worse - spoofed. Many systems can be inop and the flight can legally dispatch according to the MEL - leading to reduced redundancy, all of which needs to be managed by someone or something to within acceptable levels of risk. Automation is great when it works, but every single day airliners lose comms, lose radars, lose TCAS, Rad alts, FMCs, Autopilots, GPS etc, and are safely landed by humans without you ever hearing about it. Due to the glacial rate of evolution within aviation - particularly in regards to certification - pilots are going to have here for quite some time.