I have never seen that, ever.
I'm sure it's possible, but I know plenty of large families and the most noticeable thing about them is that the older siblings take care of the younger siblings and the parents take care of them all.
You are fortunate then. But there are definately families out there that are not parenting their large broods.
Big is not always better. Sometimes, not always.
I have never seen that, ever.
Go to any large city, find the low income neighborhood and you'll see it.
My sister-in-law had 6 kids, and didn't do a great job raising them. One of them has been in and out of jail. Another one is in her early 20s and already has 4 children out-of-wedlock.