I can see how this is related, but not the same as living off-grid.

Also, of all the "off-grid" people I know, including those who could probably 100% forgo trips to the grocery store (most will buy goods a few times a year), I think there are none who would thrive if they had zero contact/benefit from the "grid."

Energy, goods, internet, clothing, etc...

And here come the hardcore preppers!

You can engage with society without being 'well adjusted' to it. The Franciscan Friars are a great example; St. Francis was obviously not interested in 'conforming' to what he saw as a society in need of reform, but he also didn't try to hole away in the hills.