The team over at DxOMark is recognizing that drones are quickly becoming the next big thing in photography and has started testing the cameras on those.
Currently there are a few sensors tested and among them the best is the DJI Zenmuse X5S which happens to have the largest sensor - a micro four thirds one, like the one on the Olympus cameras or the Panasonic GH5.
DxO tests a couple of things - a sensor's color depth, its dynamic range and its low light capabilities. You can go ahead to DxO's website through the Source link below and compare the drone cameras to any of the other devices they've tested.
I think DJI specialised to make drones long ago. Gopro is just new to this.
Its only a matter of time before DJI will overtake GoPro. GoPro is just like Nokia in their prime. Always complacent until the competition left them for in the dust.