Because that's how it works to be part of a society. You sacrifice some of your work to raise the quality of life of everyone.
Roads, parks, power lines, communications cables, police, welfare, healthcare, sewage, electricity, clean water, healthy food, safe consumer products, clean environment, justice, protection for the vulnerable, duck wetlands, women's shelters, protection of creative works... These all cost money, and you pay for them with your taxes. Not everything goes equally to everyone, and not everything benefits everyone (by necessity), but the aggregate benefit is huge.
The point of taxes is to pay for things that benefit society as a whole. Having children, especially in high income countries, is not only important but also extremely necessary. I don't like children either but I also don't want to be the last generation to inhabit the planet. And it's important that children have support early in life to be successful.
Roads, parks, power lines, communications cables, police, welfare, healthcare, sewage, electricity, clean water, healthy food, safe consumer products, clean environment, justice, protection for the vulnerable, duck wetlands, women's shelters, protection of creative works... These all cost money, and you pay for them with your taxes. Not everything goes equally to everyone, and not everything benefits everyone (by necessity), but the aggregate benefit is huge.