You don't actually have to do that before having a child, you can do that while having a child.
If you are not wasteful (constant new things, fancy vacations etc), young children are not expensive. It really only gets expensive when you have to pay tuition.
Anecdata point: my wife and I chose not to have kids for the reasons outlined in the GP post (and more). Mortgages are so large these days that for people lucky enough to even be able to own a home, becoming comfortable enough with ones financial position that you feel you could give a child the kind of upbringing that you'd want for them (equivalent to your own, for example), takes long enough that the window of fertility is past. Plus, honestly, the world seems pretty bleak at the moment to myself and a lot of my smart friends. It's raining PF[AO]S, the climate is an unsolvable disaster, microplastics are everywhere, we're on the brink of war, inflation is rampant, housing is completely unaffordable, politics is a polarised mess, who'd want to bring a kid into a world like that without at least some kind of solid financial certainty? (There are positives, the world has it's amazing moments too, but hoo boy there are a lot of challenges to be solved).
Your list is basically "recentism" where current things seems much worse than old things. In modern history the world has never been cleaner, never been safer, never had less war than it does right now. The climate is not going to be a disaster, the worst that will happen is a ton of people will need to move - but the climate will change so slowly you'll barely notice. Inflation has been worse in the past, and while polarize politics makes me quite upset, I suspect it's been worse in the past.
This isn't about discrete reality. It is about perception and self-rationalisation. Unlike economics, I don't think people are "rational actors".
There are more factors nowadays that convince people (rationally or not) that bringing a child into this world would be to give someone the gift of a lifetime of misery.
My irrational argument for having a child? To combat the stupidity of the next generation. If the good people (And who doesn't think they themselves are the good guys?) don't procreate then the evil/stupid win by default.
"Default? The two sweetest words in the English language! De-FAULT! De-FAULT! De-FAULT!" - Homer
