They could except for regulations. It is the same as driverless cars only much more disastrous potentially. You wouldn't want them crashing into other planes or flying into buildings.

I saw a drone demonstrated by a startup in 2005-2006 that could leave the airport in the morning and do aerial infrared photography all day and return at dusk. The FAA would never give them permission to fly and the company failed. Saw another company around 2015 show me the exact same thing except they had a chip that let them avoid aircraft and geofenced them from entering space around all airports. The FAA let them do a preliminary test which they passed but never let them have permanent permission so they ran out of capital and failed.