witcheseve what is you don't understand about this?
If everyone gets CB, it's a safety net. Here's just one example ...
Imagine your friend is suffering DV. She has two children. She works PT, and her DP works FT. She has put up with the DV for a long time, but she doesn't see herself as suffering from DV. Her DP says he is sorry and is working on his anger issues, and she hopes it will be OK in the end. She wants to keep her family together.
One day, her DP goes too far for her to bear any more, she is in fear of her life. She takes the children and runs. She has to cut all contact with her ex to feel remotely safe. This means leaving her job. She suddenly has no income. Now although officially she is entitled to means-tested benefits, this will take time to process.
As well as dealing with being suddenly homeless, and the immediate needs of her children, she will have to go and fill in forms and find emergency accommodation.
Having never dealt with the benefit system before, she's not really sure how to go about it (and it's not a quick process! I've done a "rapid reclaim" in RL which took a week and 5+ hours on the phone!).
There are DV organisations which will help, but she's never been in contact with any of them and doesn't know where to start. While she is working her way through the maze of bureaucracy that is the benefits system, she does at least have CB to buy food. The few quid she gets from CB stop her going home in desperation to feed her children.
... Or any one of a zillion other scenarios. Use your imagination - jeeez!