A permanent fixed connection to the ground severely restricts a drone's mobility. The contact to the ground should be designed to be as free as possible from repercussions on the flight characteristics of the drone.  Therefore, a felixible connection by means of a rope, a cable or something similar must be chosen. This leads to the problem that the string can get caught in one of the rotors and thus cause the drone to crash in the worst case.
In addition, you need two hands to control the drone including its camera function. A second person is therefore needed to ensure that the cord does not get caught in the rotor.

The flight time is limited by the battery capacity. The maximum flight time indicated by the DJI website is around 30 minutes. For certain applications such as video surveillance, taking video of a football game, etc.. longer flight times are required.