My current junior applied to a zillion simmer internships at federal agencies, companies, etc. She didn't hear a thing from any of them. She has top grades, course rigor, references and full time work experience (summer after freshman year). In retrospect it was a giant waste of time--both of hers and the teachers that she had wrote recs.
She ended up working full time and volunteering at a hospital (which was also a remarkably competitive process)
The only kids I know who got internships did so through family connections in private industry. I'm sure the federal ones come through for some kids, somewhere but it's probably 1:500 odds---someone gets them but it's not easy to be the one who is chosen.