The Amish do many things correctly.
No vaxxes is one of them.
No high tech is another one.
The focus on a lot of time outside, a lot of exercise is another one.
A strong social structure is another one.
What science would do (if it was not just stupid propaganda) is tease out the impacts of each of these on both severe and moderate autism.
I suspect all of these are relevant factors to a greater or lesser degree.
Sounds like a decent life. Humanity isn’t mature enough for social media or direct democracy.