All in, OPs family will have cost/claimed £1.5+ million in taxpayer handouts over the course of them all growing up with one thing and another. All the kids will be entitled to full support at Uni too vs parents who earn more on paper but due to tax take home much much less.
How many working parents would love the luxury of never having to work FT and/or to self actualise and study a subject of interest.
Here’s the rub too, a single carer with no kids but caring for sick or elderly relatives gets practically no help or support in contrast.
OP you say you’re ‘very lucky’. You aren’t, you’ve gamed the system intentionally or unintentionally and hit the jackpot 🎰 income wise with many people much worse off now paying you for your irresponsible actions. How is that anything other than unconscionable?
You can’t put them back, but only you could have chosen to use contraception and be reasonably responsible.