Both of you are right.
It's difficult, but how difficult depends on the task you set. If the task is "maintain manually initiated target lock on a clearly defined object on an empty field, despite the communications link breaking for 10 seconds" -> it is "give a team of coders half a year" difficult. It's been solved before, the solution just needs re-inventing and porting to a different platform.
If it's "identify whether an object is military, whether it is frienly or hostile, consider if it's worth attacking, and attack a camouflaged target in a dense forest", then it's currently not worth trying.
As far as I know, the routine in the current war is - the AA gun is on a truck that moves 80 km/h, the drone comes in slower than 300 km/h, one or multiple truck crews position themselves on likely vantage points for intercepting, and the rest is luck.