The topic has been discussed in depth. The reality is pilots are maybe $70-80k/year whereas drones cost a lot upfront and don't necessarily fly fault free at 12-14,000 ft. Cessnas are cheap and easy to deploy especially through Nearmap's contracted aeroplane company.
If drones did have an economic advantage nothing stops Nearmap from mounting their cameras to a drone and using them.
NEA Price at posting:
$1.83 Sentiment: Hold Disclosure: Held