This comes down to whether you were made aware of this when you interviewed for the role, and did you make them aware of your caring responsibilities when you were assigned your year group.
Is it that you don't want to leave your 4 year old or you can't- such as you are a single parent, or child's Dad works away?
Residentials are hugely beneficial for children, especially in our current society when their independence is limited by anxious parents and social media influences. Our school is introducing them at year 2 and year 4 as well as year 6 which is amazing, and testament to a very dedicated teaching group.
I do residentials with girl guiding, so not paid for any of the hours, and it really is a fantastic experience to see them grow and thrive. Yes they are exhausting, yes you have to deal with anxious parents and homesickness, but the sheer joy on their faces when they move out if their comfort zone and acheive something they never thought they could, is priceless.
No, the parents probably don't appreciate the work of teachers, volunteers as much as they probably should. But I'm not there for thank you's from the parents, I'm there for the children. In this world there will always be those who step up for our young people and those who expect someone else to, so ultimately its up to you to decide which of those groups you fall into.