I believe quite a few of these kids are used as sleepers. (Red Sparrow) What do you do when you've accumulated power but you're only one man/woman? You can only spread yourself so thin, hiring people is risky because they have their own plans and they like to talk. Kidnap the kids, sponsor them, mold them to be whatever you need, inject them where you can into government/un/banking and take control. A nefarious group of people working together could quickly over take any system with their own personal army of puppets.