https://ifs.org.uk/taxlab/taxlab-taxes-explained/income-tax-explained
It is not really that simple Tristar. I expect the poster has done calculations.
there are two points where your marginal tax rate goes to 60% or 70%. This is where you suddenly (my understanding) become ineligible for certain benefits/tax credits. It makes sense to stay below those lines, either by putting a huge amount in your pension or by reducing your hours.
i saw another chart somewhere- but have not been able to find it - which shows that up until a certain income (maybe £45?) you get more out of the system than you pay in (healthcare, defence, roads, etc). When you have multiple children in state schools, obviously you get more out.
With regards to the VAT, a lot of people using the private schools were making a lot of money but also paying a huge amount of tax and getting no benefit (chart is marginal tax only). Unless you are extremely wealthy that means long hours, lots of stress etc.
By reducing your income massively (part time, putting all you can in your pension), you suddenly get eligible for a lot of benefits such as child benefit, tax credits etc. You also get a lot more time with your children which is lovely 😀.
there is an initial frustration that you worked so hard, paid so much tax and then had to pay additional tax in the form of VAT. When you relax, move to a place where the state schools are better, reduce you work massively, top up with tutors as required the children are still ok.