Both major parties support this system. Some Republican interests enjoy the access to dirt-cheap labor. Some Democratic interests want immigrants to be able to find jobs despite it being illegal to employ them.
So we end up with a system where employers have no easy way to verify that an employee is who they say they are and has a legal right to work any specific job.
This is such an easy problem to solve, but entrenched interests would rather we all play dumb and occasionally slap a business on the wrist when they get too far out of bounds.
I’d be curious where these kids end up after this. My guess is they will not end up in schools but will rather end up doing undocumented farm work.