The problem with the entire series is that it's designed to encourage people to generalise from the cases described as 'young parents', 'single parents' etc.
Callum's parents so obviously need lots of support. It seems so very obvious to many of us where they're going wrong, but they clearly don't have the life experiences or social networks that would help them to do the same. It's also hard to help them because they are fearful of professional involvement in their lives, and feel judged etc. I'd hate someone coming in and scrutinising my parenting. I'd find it really hard. It takes bravery to accept the kind of help this family need. Well done them for doing so.
They must be totally exhausted. I keep watching and thinking about how much better life could be for them. Enough sleep and not feeling life is a constant struggle against their children would make such a difference.