One of our local survey operators does a lot of work for NOAA. Last year NOAA got their hands on a predetor or something similar to do the same job at the same time. Just the initial cost of the drone makes paying humans cheaper. Then, you have the fact that the drones can't discriminate what they're taking pictures of well as the human that's going to actually use the data and NOAA is still waiting to get their data back over a year later from the drone.
Oh and they crashed one to, so there's a few million down the crapper. But they actually crash a lot if you look at the stats from the last two wars. At rates deemed completely unacceptable by people that have to care about money.
Humans are still cheaper. When that changes, then we'll start to worry.