State schools have people that got into MIT, but didn't go for financial reasons or family reasons. Nobody at RPI got into MIT because if they did they would have gone to MIT (maybe some rare exception exists, but this is generally true).
School admission is obviously not a perfect indicator of ability, but I suspect while the average and median may be higher (and more tightly distributed) at a school like RPI, a state school will have a lot more outliers.
Everyone is fighting for students from the super selective schools and state schools are largely ignored - students either need referrals to get interviews or jump through a ton of hacker rank like hoops.
This is even ignoring the 'diversity' angle - a lot of really great people are missed because it's hard to break in without knowing someone or having the right credentials.