'Spotters are pretty much redundant'.
No, they are essential. It is extremely beneficial to have two people doing pre flight checks, fast jets are not always located by sound, there may be more than one aircraft, plenty of other air users make little sound, the drone pilot may be concentrating on a monitor, people may encroach on the landing area, and the sound of the drone itself may mask other sounds.
If flying in a controlled environment such as a model airfield, it may be acceptable to fly solo, but in my opinion flying solo in any area accessed by the public is not safe.