I suspect that the policy is popular with the 90% of voters in the UK who earn less than £80k and that politicians are not very concerned with the ambitions of the rest of us (frustrating as that is when paying London rent).
To me it appears as though the success of the right wing politics everywhere is that they made socioeconomically disadvantaged people identify other socioeconomically disadvantaged people and the middle-class as the cause of their suffering while somehow becoming sympathetic to the uber rich in hopes to one day belong. And to me it’s clear that if we taxed wealth and high incomes fairly and removed the loopholes to level the playing field we would not even need these discussions to begin with because we simply had a well financed social society and the rich would still be rich, but maybe not so obscenely so.
I don't really think people understand it, it's quite hard to explain and on paper it just sounds like the person is wrong.
The maths for one child for me works out at ~£10k childcare bill without the free childcare vs ~£4000 with free childcare + tax free childcare (for three days a week). Even that doesn't sound too bad but it's the combination of that, the loss of personal allowance and the fact I still have a student loan that means the actual number of how much I have to earn to break even on losing it is something like £30k more than the actual cut off.