@MrDarcysMa - I can totally relate to what you have written in this thread. I'm 36 with no kids, I'm probably about 85% not wanting kids and 15% wanting kids. I love kids but the main reason I won't be having them is I can't afford it. I still haven't yet got on the property ladder and I have financial goals I don't think I'll reach until my early 40s, and if I have a child soon then it will delay me reaching those goals in the long term.
If I had loads of money and could afford a nanny, I'd maybe have them. But then I don't want to give birth (after seeing my sister do it, it looks horrendous) and I don't want to carry a child or breastfeed. I also love my sleep and don't want to be woken up in the night.
So if I don't want to be giving birth to a child, or look after them, then it looks like I don't really want a child.
As for the question of "who will look after you in your old age?" Personally I have no contact with one of my parents, and I've known some other people who don't have a lot of contact with theirs. I am one of 5 and only see one of my siblings, the rest of them we have nothing in common and don't talk that often.
There's a lot of uncertainty around how family relationships could turn out so it's not possible to just assume you'll have a child you actually like, who also likes you, and who will want to take care of you in your old age.
I know too many people for whom that scenario doesn't fit.