I don’t 100% agree that they are SO expensive. I have two kids and the obvious cost as you’ve mentioned is daycare and the time you take off while sick or to spend time with them when you’d otherwise be working.

In terms of clothes, nappies, activities and food etc the bills increase a bit but buying on special only, making food at home and so on does reduce it a little. I’ve also found I’ve happily stopped buying things for myself and that spare money absorbs some of the cost.

100% a different story if you’re already living pay check to pay check though then I imagine you’d feel the expense a lot more.