In the 2022 movie Fall: seeing as the girls established that there was mobile phone reception at - or near - the base of the tower, why would Becky attempt to send the drone with note attached all the way to the diner several miles away?
Flying the drone with a mobile phone attached to the base of the tower has, I believe, a better chance of success. Plus the distance covered allows for repeated attempts. It's 2000 ft to the base and several miles to the diner, so I dare say the latter, chosen option was always going to be a one-way trip.
Keep in mind that a mobile phone sent to the base of the tower via another means provides the ultimate salvation.