>It shouldn’t surprise anyone that good schools have better admission rates to good universities.
The actual answer is probably "it's complicated." MIT also doesn't want to filled with Stuyvesant and Bronx School of Science grads. (Though last time I saw the numbers they did admit a fair number anyway.) 5% of my small high school graduating class ended up at MIT but that was a long time ago and I assume that wouldn't happen today.
It shouldn’t surprise anyone that good schools have better admission rates to good universities.