Well that UAV still had a pilot... Remotely piloted. Placing the pilot in a remote location decreases SA. The gain is that you don't lose a human life in the event of aircraft loss. Taking a pilot out is good when a pilot doesn't want to be there, fr example long loiter times, aka when you need long persistence like the predator.
Surprisingly, these unmanned aircraft need MORE personnel to get them flying and keep them airborn. There is a manning shortage for "unmanned aircraft.". Ironic.