You'd be shocked how much candy that doesn't contain nuts, might contain enough to kill someone with a severe allergy. Half my halloween candy when I was a kid, every year, would end up going to my mother for that exact reason.
I'm sorry you feel that way too, I'm in the same exact boat so I know what that feels like... I'm just waiting for my older relatives to pass so I don't hurt them and then I can finally stop existing.