no one expects it to stop 100% of people. but hoards wont be walking on through anymore. guards that travel up and down the length will catch holes.
every other wall in the world (borders) is extremely successful.
isreal's wall stopped 1000s a year down to less than 50.
mexico's southern wall stopped most of the south americans.
we have 30's of thousands that we are even aware of per year. that stuff is far too many.
you can have reform without spending billions on a wall
can have both and it saves even more money.