Agreed, especially in flight mode, though on EK with in-flight wifi it's tempting to stay connected. Also if one likes to play games it drains the battery. Other travel-related activities are also battery-draining. Uber, Google Maps, trip tracking apps, e-mail on the go, constantly checking and playing around with the phone while bored waiting to board...

Though my battery hardly is used in-flight, the ancillary activities related to flight drain it more than average.