ANY school can be cruel (especially for a shy kid) if it isn’t the right fit.
I’m a huge proponent of LACs as my D had an absolutely fantastic expereince at one. Yet, when we toured LACs we felt that many of them had a “vibe” or “personality.” My D eliminated a number of LACs after her list after an initial visit (“too artsy”, “too preppy” etc.). So I tend to think that fit is very important at a LAC. And, based on my S’s feelings I also think that the intimacy/close-knit aspect of LACs is not for everyone.
FWIW at my S’s mid-size university he had typical class size of about 30-35 students. He had only two larger lecture classes which were capped around 60 students (which was also the max. my D had for a couple of lecture classes at her LAC).
Bottom line is (assuming all options are affordable) listen to your child and follow his/her lead about what specific colleges and what types of colleges are good fits.