Sit down meals are a chance to slow down for an hour, not choke down a meal, converse and come together as a community. At the same time the OP is complaining that schools are go, go, go with too much stress, seated meals provide a pause in the week to recognize that the boarding school experience and community is more that just grades and studying. If it was my child complaining, I’d encourage them to relax a little and engage in the seated meal process. If he’s finding it dull, challenge him to think about a topic to discuss and bring it up. Glass is half full, not half empty.