85,000 now missing migrant children,
contagious diseases,
Migrant minor work slaves.
The list goes on.

Looking at the links you posted that are supposed to support your assertions of Biden's incompetence doesn't exactly present a rousing defense.

abcnews does talk about children being employed at fast-food places, etc, who are underage, but there isn't a single word about their being migrant kids. Comments are made about kids working in the evening after their school day, etc etc. The issue is the illegal hiring of underaged children, including giving some of them responsibilities handling dangerous equipment. But "illegal" is applied to the work the children have been hired to do, not with their presence in the UlS.

And the article on the 85,000 "missing migrant children" makes the concrete point that it is not a question of children who have somehow disappeared and cannot be found. It is unaccompanied children who were all cared for until they could be placed with a parental substitute....another family member already here or a vetted sponsor..... The requisite follow-up phone call a month after release was not successful in those cases. And as far-right Republican Andy Biggs said to the person in charge of this: 'I'm not saying you lost them, I'm saying we lost contact with them." (The actual data were uncovered by the NYT.)