The question of "why should I fund other people's choices" could equally be asked about pension.
When you're getting a pension from the government, or frankly, any services you don't pay for yourself at all when you're no longer working, whose choices exactly are paying for it?
It doesn't take a genius or economist to work out that is the choices of people to have children that create a working population who can pay for people in their old age who are no longer working.
Even if you saved and invested and paid for all of your pension yourself, you must realise there have to be people of working age to work and provide services that you need. Without those people being born to, I don't know, other people who made the choice to have children, you'd have no food, bin collection, maintained roads, doctors or anything else in your old age.
Without people having children there would be no society.
Sorry, having children is essential to society not collapsing within a generation.
Who is it you're relying on to have those children to keep society functioning?
Other people choosing not to have children is a choice everyone in society has to pay for as well.
Let's stop pretending we can function without people giving birth and raising kids.