The left is trying to stop both.
No, we do not. Your ilk, on the other hand, are obsessed with the former at the contemptrous expanse of the latter.
The number of children and the effort that can be invested into each individual child are inherently in a trade-off, one with many different variables, and different species have evolved to fit different optima. For a lot of life-forms, this very much tends to be very much purely in the former. Humans, on the other hand, are an excaptionally strong case of the latter, very actively raising our young for well over a decade. And constant pregnancy is not actually the natural state in humans, but one of several side effects of the agricultural lifestyle that led to the emergence of patriarchy in the Bronze Age - breastfeeding strongly suppresses fertility, but with sessility and the avaibility of lifestock milk, this natural spacing-out of pregnancies diminished.
Human pregnancies are long and disabling. Before the advent of modern medicine, human childbirth is extremely risky for btoh the mother and the child. Human children are helpless for a very long year. As a documentary on “Venus” figurines and generally the new outlook that “Man hunt mammoth to feed woman!” is nothing but projection of our own society’s traditional sexism pointed out, to the mesolithic nomads, fertility would not have been all that desirable - no, the important thing would have been to bring the children you have through.
I desire very deeply to be a parent myself. But it is a sacrifice, of not just plenty of money but also plenty of things far more precious, for the rest of your life. But, the thing is, I know for a fact that, for a lot of people, yes, this sacrifice is more than worth it, and they would not want to have missed out of it. Amd it is from this perspective that I find all these fundies, who take their children for granted and who assume that, if people have the choice whether to have children, NO ONE would, so deeply alienating and disquieting and even insulting.