It really depends on major and on the kid and on the comparable school. Do you really believe that every kid at an elite school is there for the life of the mind and the kids at slightly lower ranked or public universities are not? There are kids at the most elite colleges that are smart, driven toward their professional goals, privileged and not all that interested in intellectual pursuits… Would your kid have less intellectual curiosity and value if he/she got shut out of the top 20 and had to attend a (in your opinion) lesser school? We are not talking about Harvard vs the local college that accepts anyone with a HS diploma, but schools that get the students that didn’t get into the elite schools, sometimes because the rejected students were more interested in learning than in chasing grades (and, of course, other times because they just didn’t do well enough).
And, as @austinmshauri points out, depending on major (bio for example) there are many more undergrads that want to do research than there are positions for undergrads in active, grant-driven research labs even at the best schools.