Ilovecheese
I do think that single parents should be made a special case, at least for a couple of years because of the effect of single parenthood on the children. When children have lost a parent being in the home whether through death or separation, the last thing they need is for the remaining parent to be absent for more hours of the day than they were previously. I think looking after the mental health of children pays dividends in later years and probably saves the state money in the long run.
You may be right, but as I said, there are couples earning less than single people, so subsidising single parents (as opposed to parents) is divisive. There are plenty of couples working round the clock to keep the family afloat (as represented by the couple in Sorry We Missed You), and it would be very unfair to make a special case of a single parent who is, say, a lawyer, and not them.