The reverse is true though: many couples wanting kids will bail at the price to pay without serious aids, and feel it would be a disservice to their kids to raise them in too poor conditions. Many couples won't make long term plans (including marrying/having kids) if they don't see a stable financial path down the line.
Now, the gov aids and labor laws provisions need to be significant to have a visible effect (e.g. a hundred or two bucks per child per months won't cut it). I don't know how far Germany went.
I was looking at the comments on the r/germany about wanting kids but not being sure to be able to "afford" it [0]. This is a pretty common refrain for the Japanese youth as well, even going to down to not being able to afford dating as they're expected to spend money on courting, wining and dining in general.
https://www.reddit.com/r/germany/comments/14jhwdn/after_10_y...