Having many kids is often because of a necessity like cheap workforce for the family or high child mortality.

Kids can be fun but also can be really exhausting.

How many kids are really born just for having am offspring and not because of other reasons.

If people can consciously decide to have or not to have kids my bet is on falling birth rates.

For stable population you need two kids per couple and first could be an eye opener that children are a lot of work.