None, it would be a net loss.
In your opinion. And you're free to hold that opinion.
However, I've spoken to retired military commanders and Border Patrol agents who disagree with you. Former Chief Border Patrol Agent Bill King will speak at the rally in favor putting the military on the border.
Can I ask you, do you live near the border? Have you visited the border area to see the current invasion? There are people who are far more familiar with the current situation who may know a bit more than you do about it. Some of these people support putting troops on the border.