Not true. First of all, the new Toyota Prius is listed at 50 miles per gallon and gets in the 45 mpg range in normal usage, so you picked a bad example, although I know what point you're trying to make. Having said that, the differential is much greater for the advertised specifications of the P4:
In "real world" conditions, the craft goes nowhere near it's advertised specifications.
If Toyota sold the Prius was advertised to go 50 miles per gallon, and in normal driving it went 20 miles per gallon, there would probably be legal action.
Being that I don't have wireless security cameras, I cannot address that specific point that you made.
But the final point here is that you attempted to be mildly dismissive of the range extending options, when the very purpose of them is to achieve greater range and penetration in "normal" environments because DJI significantly inflates the capabilities in their specifications.
P.S. Btw- the Prius mileage would probably be better in NYC traffic because it would be running mainly on the electric component of the hybrid engine. That is why now all new taxis in NYC are required to be hybrids