No, not really. We certainly have the technology to support the wall with drones or whatever is needed.
Of course we have the technology, but drones without a wall and increased manpower are futile. The drones can certainly spot those coming across, but how long do you think its going to take 'manpower' to get there?? Keep in mind that the southern border is appx. 1,954 miles long and there are only appx.16,000 border agents.
A wall alone isn't going to stop illegal immigration, but a barrier is definitely needed to aid and assist technology and manpower.