I did go on a few year 6 residentials when I was a school welfare officer.
Like I said upthread, school residentials are totally different.
The children are with teachers they know and trust, the teachers know them. They are with the same group of friends they are with day in, day out. They all knew me as I was the “school nurse” to them. They Would come to me in school if they were upset, school trips no different. You always had some who were homesick in the evenings, but we would sit and chat, they would talk about their worries as they knew me well, I would often make them laugh and they would be okay and happy in the end. Their friends would jolly them along. Lost parents wrote letters for children to take, which was always such a comfort to them.
We made it clear to parents that if a child was very upset, we would call them. I never had to through, they were always okay after a few mins, and it was usually as they were tired or hungry. I always had a stash of sweets to cheer them up, share with their mates.
As for bullying, well, they were in their class groups. The school I worked at was good with those situations, we didn’t have any real issues. Children were grouped into their frienship
groups, we knew them so we knew what worked.
The children who really would have struggled didn’t go. They would stay at school for the week and go on little day trips and have activity days instead - the parents always made the right call with that, there were some who would really have struggled with 5 days away from home, and that’s okay!
my children have always gone on school trips, but not camps, although the two older ones did DofE, (although one dropped out after own trip as he though it was pointless and boring, which was fair enough).