I don’t think they’re coming “across” the border anymore; I think its more like they’re coming in “underneath” the border (tunnels).
You are most correct near cities like San Diego, Laredo, but the thousands of open miles where the Coyotes know there are one or two agents for hundreds of miles, they still just drive or walk across, and its less expensive and dangerous than building and using the Tunnels.
This isn’t about letting some poor migrant better their life in America, its about dirty money and feeding ample supplies of Drugs to the Inner Cities where the Drugs and Profits are distributed easily with virtually no significant risk.