Yeah, I think that so long as childbearing is largely pushed into the 30s, you are going to see a reduction in kids overall. Some will not meet anyone, some will be infertile, many will only be able to manage one. The fact is the 20s are women's most fertile 10 years.
And it's not just pushed into the 30s, there are people who are pushing it into the early 40 as well.
I've wondered if it might not be a social good in many ways to make a real effort to look at the length of time we have young people in education. I am all for general education, but the fact of the matter is we have many jobs asking for degrees that are unnecessary, where people could learn on the job, in apprenticeships, or even forgo university altogether. It's a huge cost to society, and it's a cost to individuals, and it also an indirect cost as it keeps them out of the workforce for something like four years - often more.
So you have people not even beginning earning until about 25, they have a debt and want to establish themselves. Plus, you are not going to give that up for kids, you've invested too much.
There could be a lot to be said for most people going to work by the time they are 20 and earning, starting without a debt, or possibly in some cases for women to have kids fairly young (assuming a reasonable partner) and then going into a career afterwards, which would be much more manageable if they didn't need four more years of education.
It would need a real change in attitudes to education, professionalization, and mothers though. And we'd have to stop seeing people in their 20s as children, too immature to do anything really important. The reason our young people are like that is because we don't give them real responsibility, not because they aren't capable.