I can only answer for myself, and I gave birth to my three children decades ago, before the costs of rearing them became astronomical.
I don't think it is a mandated step to take after marriage. Some couples don't desire to have children at all, and that is their right. It's preferable, I believe, for people who do not feel maternal or paternal to avoid bringing children into the world if they would not be devoted and competent parents.
As for myself (which is how I began this comment), I had a strong desire for children and loved them dearly when they were born and while bringing them up. Even though they are adults (and either middle-aged or nearing that point), I still want what is best for them, worry about them--something that doesn't automatically end once they become grownups--and feel proud of them. It wasn't that I wanted to found a "dynasty", but simply that I had a maternal urge that would not be denied. I'm glad that I had my children.
On the other hand, with the turmoil and uncertainty currently prevalent in the world, if I were a young person contemplating a family, I might hesitate. It is frightening to think what babies born in 2011 might be subjected to in the future. Climate warming changes, wars all over the globe, economic uncertainty, rampant crime and terrorism...all these would be factored into a decision. It's a lot to take into consideration.
Makes me glad my children were born "way back then." Now I worry about the future of my grandchildren and great-grandchildren.