Am I wrong for this?

Im a package handler, sometimes it gets insane and it feels impossible to keep up when im getting hit so I just let the packages run on the belt, I just stop caring and miss them, ik someone has to pick up my “slack” but it just feels wrong to be running around the belt, im not a slave and I’m not gonna hurt myself over $17 an hour, managers seem to be bothered my this, maybe if they slowed down the belt or if we started earlier I wouldn’t have these issues, one time they literally said that to make up for starting later we’d have to work more which means less hours and more work, it’s ridiculous