What we don't have with our drones is an ability to correct the altimeter based on weather-caused variations. However, this inaccuracy is pretty much irrelevant if you're trying to detect if your near to 3000m/10,000ft, as a condition of takeoff...
I guarantee you that if you put on some wide-angle lens glasses and drove your car, you would have a crash, because you would be mis-judging distances. Have you ever noticed the etched writing in right-side rear-view mirrors, "Objects in mirror...
Because it can determine approximate altitude from the barometric sensor. While variation at a fixed location can be as much as 1 inHg at extreme weather, typically pressure variations result in no more than several hundred feet max altimeter...