Why having more kids is tougher nowadays?

Today, I went to a small coffee shop which need to share table with someone else most of the time for breakfast. Actually eating and drinking (I mean coffee/tea not beer) at coffee shop is what I like to do.

I overhead an conversation within an uncle and another auntie with a baby who is her grandchild. This auntie is telling the uncle that children nowadays are very hyperactive resulting it is too tired to handle more kids. Kids in the older generation are less hyperactive and more obedient, it is pretty easy for taking care more kids at the same time. I remembered my parents able to take care 3 of us in the past. Of course 3 of us are quite easy to be taken care of. When I check with my parents if they are able to take care of my 2 young children, they said they are not able to handle 2 at the same time. I confess that my children are more difficult to handle compared to me and my siblings. So, the ratio became 2 super persons can only handle 1 young kid at a time. 

Nonetheless, this is not the most important factor for not planning for more children. This auntie has another 3-years-old grandchild whose parents sign him up for additional lesson in childcare that cost $100 a month and the lesson is only 1 hour a week. The cost to bring up a child is too expensive nowadays. Other classmates are attending the extra lesson and my child wanted to attend too. Therefore as a parent, I must sign him up as well right? This is not the first time I heard this. Before this, I heard of another auntie sharing her son need to bear the cost of expensive childcare, school bus fee to and fro childcare, maid to handle housework. Both the son and daughter-in-law are working to foot for all these high expenses for their 2 children and they are not able to afford more than 2 children.