Because there are no countries super pro-baby. Some countries have better policies, but still babies are really expensive to rise. Of course if you want them to grow in decent environment, with separate room for each child, good school, hobbies etc.

Year or two of maternity leave helps, but parents will struggle untill school starts.

Few hundred euro per month will help, but not too much, will not cover the difference in rent of bigger apartment.

Career? Forget about promotions for few years.