We have given the wrong advice to young people for two generations WRT having children. We have said "get to know your spouse, get settled, be more prepared for parenting." But children get by on what we feed them (within reason) and vegetables are cheap, and babies don't have any awareness of whether they have to share a room or even a bed with siblings - for years. We talk about wisdom in order to raise children, but really, I learned with my first foster child, who was eight when I was not yet 24 myself, that the job does not require much wisdom most of the time, it requires being present. A sandwich needs to be made, make it. A diaper needs to be changed, change it. This sort of crying means tiredness and you need to get this four-year-old home. That's it. What is needed when children are small is mostly energy, and at 38 you have less than you did at 18. The things that make parents feel more ready are largely irrelevant to the child, and by the time they are old enough to make comparisons, you are 10 years older and wiser yourself. And now you have experience to boot.
For a decade I have been telling young couples "Have more children and worry about them less." Because that seems a bit shocking I do expand on the topic and develop it. I think I will now amend that to "Have more children, have them younger when you have the energy, and worry about them less."
Within reason, of course, but people who are going to be decent parents anyway usually don't have any new magic they are going to learn by waiting an extra five years. The responsible ones are usually responsible already. And observing the little ones at church today, darn but you need energy as virtue #1. We have clearly underrated that, to the detriment of a lot of young moms.