Each minor has about 8x the chance of winning and the program has over twice the funds per kid in the population than per adult. Proportionately speaking the overall pot for kids is twice the size of the pot for adults.
In raw dollar amount, you might think so, but... it means the kid will likely enter the working population with a college education, and no debt to speak of. That is a huge benefit.
I will likely be paying off my student loans until I die. I have friends who got through school without debt, and they've already retired, because they could save far more than I could.