The USAF won't disclose the embarrassing number of multimillion dollar UAVs [Unmanned Aerial Vehicles] that have failed to returned to base. . . !
As to automated passenger flights: all is well as long as there are no system failures, nor other phenomena, such as moderate clear air turbulence which could kick off the autopilot(s) . . . .
Are you ready to get aboard an airplane without a pilot...?