All of the existing automation systems are predicated on the existing use cases. It's a centralized system where humans evaluate that data, and then issue direc

All of the existing automation systems are predicated on the existing use cases. It's a centralized system where humans evaluate that data, and then issue directives/clearances based on them. ILS will not work on a large parking lot, the antennas are huge, transient objects attenuate the signal making it unreliable, all kinds of monitoring is needed to detect deviations and automatically shutdown the system if necessary, etc. A whole new precision landing system is needed to fit into smaller space requirements you're suggesting. And now there are new problems like people walking around the landing zone and having physical access to the ground based equipment.