Why isn't any party making individual benefits a plank of their strategy

I know there are problems but surely we have long outgrown the days when the govenment looked to see if my nightie was next to your pyjamas in order to tell me that I am financially responsible for you. Family benefits seem to have brought the idea of an assumption of share parenting after devorce to a grinding halt. The problems with integrating tax and benefits will never be solved until benefit are paid individually as tax is - look at the problems with child tax credits. I would have thought the Liberal Democrats would see it as a right to be treated as an individual and use this as a way of differentiating themselves.