Both kids were absolutely certain that they wanted small LACs (and that is where they ended up), but we encouraged (insisted?) that they apply to at least one larger school, because a lot can change in the year from when they are choosing schools to apply to and when they actually show up on campus.
It’s interesting to me that people wonder why a student should have, say, a large public on the same list as a small private, but no questions it when a kid applies to all the Ivies. They are also a very diverse lot of schools.