There is the burden of an early morning drive on another day. Dropping your kid off at noon might be a welcome change.
Beyond this, it varies wildly by school and student . Day students are on campus on weekends. Boarders go home on weekends. (Even at schools with very high boarding percentages, many kids may leave on weekends.) While I person love the immersive experience that is BS, there are students who want/need time away from it. Many day students stay through dinner and study halls every day, but there may be others who are picked up on a parent’s drive from work. Ime, it’s hard to establish a different rhythm from that of the school – if something happens after dinner, it’s hard to collect your kid at 5! But at some schools, it may work.
It really depends on what is going on on campus as,well. But there is probably a small percent of kids chose the school solely for the S of BS with little interest in the B. There are families applying to both day and boarding schools. Some may feel different after they matriculate to a BS, but some may succeed in navigating it the same way as,they would a day school.