Here's a clip of me at the border gate that people were coming through in May, 2 miles west of Lukeville. Across the fence, in Mexico, is a tire shop. This spot was picked because there is a culvert here under the border road, making a low area hidden from view.
Note this is the "Trump" section of wall (not the Clinton or Obama or Biden section). It is 30' tall. The individual "bollard" is made of 1/4" thick, 6" x 6" square tube filled with concrete with two 1" diameter steel rods in the center. Cutting through it is trivial with battery powered tools.
Note how easily I'm pushing it around. It is quicker to cut these than to weld them back up.
Walls and fences will never stop people.