Obviously when saying "universal" for child benefit and childcare funds I don't mean a separated couple could both claim it, only one just as now.
In terms of the tax, yes the two separated parents should get allowances as two separate households, for all of the reasons I explained already. They each have a household to fund so will have higher costs. That is "a feature not a bug". But each household will have only one person's time each day to earn to pay for that house or be with their children. It will be much harder for them to reach the same household income as a couple living together. So you don't compound the fact that their household income will be lower while trying to pay all the costs for the home on their own, by also taking them a higher % on the same household income that they have earned on their own as one person not two (while usually also needing to pay much more childcare as well!).
They will not be getting an advantage on you. They will always be at a disadvantage. As someone said (I think you?) of course it costs more to live separately and always will. Fine. But you don't have to "stamp down" on them too and then tax them more as well on the same income even though they obviously can earn less in half the time available each day. That is just crazy, which is why other countries have provisions in their tax systems to avoid increasing the disadvantage by penalising through tax like this on top of the inevitable inbuilt disadvantage that will always be there just through practical reality.
These people will never be in a better situation that a couple who can both earn, or one earn and one not so have no childcare to pay, or share it all as they see fit. Never. Of course not. Will always be poorer as they have to pay alone. Why would you tax them more on the same earnings and well?
It really is a very peculiar thing to the UK to see this kind of argument where people would be worried that a single parent might be better off than they are and should pay for a house alone but from less net income for the same earnings because otherwise it might be unfair on a family with two adults to earn or be with children, if the couple didn't also get to keep more of the same household income. Effectively you are saying you want single parent households doing the job of two parents to subsidise couples who have the same household income. That can never be ok, if you step back and be rational.
And as I have tried to explain, this "but it's mot fair to meeeeee" attitude makes everyone poorer in the end. You object to what I proposed even though it would not
make you a penny poorer because you feel it might help a household at a disadvantage to you and that would not be "fair" in your opinion. Even though all research shows that in the long term if this happened then it would make your household richer also: it would increase tax revenue and reduce the need for welfare so either mean better pubic services for your family or lower taxes for your family. But you couldn't bear to see some people in a worse situation get what you consider to be "help" (when actually it's just removing existing unfairness) even if it actually benefitted you as well in the long run.
That is what is wrong with the UK.
This whole thread shows the same thing, around the tax thresholds and making it pointless for people to work more, as well as the single parent issue.
People will reap what they sew. Tried to persuade people with facts and research but if UK mentality is that you would rather things don't get better for others and for you in case you feel they might benefit more than you then I can see how you have ended up where you are. And what will happen in the next ten years: it won't be good.