The Amish are extremely business savvy, shrewd negotiators, and have no issues being active members in the economy. They also own vast tracts of very valuable land (especially in Lancaster, PA). Combine that with being frugal and austere, and it's a recipe for wealth.
For childcare, their community focus let's them share the burden amongst the larger group. Additionally, children are not nearly as coddled and are expected to contribute to the family's work, and help co-parent their siblings.
Compare this to the average nuclear family: underpaid, barely any savings, most likely rents, and lucky if they have even one family member nearby that can share the childcare burden.
Since childcare is mentioned, I would be remiss if I did not point out that the Amish have a disproportionate rate of child sex abuse. Offenders often get off because the Amish community pressures victims not to testify. Victims are sent to re-education centers. It is pretty gross what goes on in plain (pardon the pun) sight. But they bring in tourist dollars. Most Amish are lovely of course, but their lifestyle has a very dark side.
There's no guarantee that buying a house will leave you richer than if you'd rented during the same time. Check out this calculator to explore your personal situation more closely, and examine the assumptions you make about growing wealth.
I know from personal experience, owning my first home, that I almost certainly would've been better off renting over that time period and investing the down payment and higher monthly payments than I ended up with having that house and equity. Sometimes you get lucky - and house prices go up and you sell at the right time (assuming you switch back to rent OR manage to then buy in a market where prices are lower than average.)
https://www.nytimes.com/interactive/2014/upshot/buy-rent-cal...
