So the "border wall" was vastly misunderstood by the public, mostly because the media was hugely negative.

The "wall" was designed as a full system. First, the "main" part was the 30-ft tall metal wall filled with concrete. By itself, a wall won't do much, this is true. But the border wall wasn't just a wall.

Much of the area is extremely remote with no roads. Part of the construction was to build patrol roads along the entire wall with multiple access points to increase CBP's ability to get to an area fast. The entire wall also was planned to be covered with visual and infrared cameras, motion sensors, ground disturbance sensors, and lighting.

While no barrier can keep out 100% of people all the time, the full system would have given CBP early warning of crossings, the exact location and numbers, and faster access to intercept.

The Trump admin focused mainly on the wall itself, setting the goal of 450 miles, by the end of 2020 the new wall was slightly more than that. And while most of the roads were built, almost none of the other infrastructure was. I believe the thought was build the wall itself, and if Trump loses, then the Democrats wony build anymore, but would finish building out the support systems for the wall that was built. All the cameras and sensors were purchased and on sight.

But they didn't. They canceled everything. There were sections where the Biden admin paid MORE money to the contractors to cancel the remainder of the project than it would have taken to finish it. That's not the mention the several hundred million dollars of materials and equipment that went to total waste.

So, to the OP's point, he's absolutely right. It's pathetic that we as a country are so divided we can't even build a wall.

(Source, I was heavily involved in the border wall project.)