500,000 children missing? Okay, where could they be. Here are some things we do know.
Many run away.
Most are taken by family, such as angry ex-spouses
Some fall into the hands of evil people that generally kill them. Not for religious reasons but for perversions.
We have a few cases of children found years after their kidnapping--alive but traumatized.
A few have turned up in homes where they were raised as natural born children.
Some have even been pressed into sexual slavery.
But what about the ones we have no answers for? Well---they could have been picked up by blood thirsty cults.
Or UFO's. Or by the Russians where they are trained as moles. Or maybe meat factories that have special hidden ingredients. The government could be running experiments on them. Perhaps they were raptured. Drug traffickers could have picked them up and use them as mules and as labor on pot farms. Rich old guys think they could stay young on the blood of children. Vampires. Werewolves. Bigfoot.
The point is---we don't know all the answers. In the vacuum of the unknown anything is conceivable. Your theory is no more valid than the above theories because you cannot disprove them. Sometimes facts can be presented in such a way as to make only one option seem likely. But the fact is there are millions of possiblities--but you have been manipulated to see only one possiblity. Just think about it.