Slightly OT: What is stopping the development of unmanned cargo aircraft? If SpaceX can deliver cargo autonomously to the space station, I somehow fail to bel

Slightly OT: What is stopping the development of unmanned cargo aircraft? If SpaceX can deliver cargo autonomously to the space station, I somehow fail to believe that flying an unmanned 747 from one airstrip to another is exceedingly complex. To be clear, I mean that the aircraft is autonomous, not that it is flown by a remote pilot. Once these systems are shown to be safer than human flown cargo planes, they technology will be widespread. After a decade of implementation, it can then spread to passenger transport as the ultimate auto-pilot. The pilot then just becomes the flight director, and takes over in case there are any failures. Sadly, I'm sure the Burj high stack of regulatory documents prevent even experimentation in this field, let alone commercial implementation.