There are a lot of prepper types out there who might be theoretically 'ready" for societal collapse, but yes, they get there by already having a stockpile of societal goods and materials and of course guns. These folks likely have a great plan for what they're doing when the bombs fall, but likely not a shred of the social and communal skills necessary to keep a functional society alive for the long term.

Maybe some of the more isolated amish communities could subsist for a while without injections of modern supplies, but even still we're talking about less an "off grid" lifestyle and more like "radically reduced technology."

Hey, I'm not disagreeing with you here, but keep in mind none of those things are necessary for survival, and most such products can last decades if properly maintained.

I think you're arguing against the most extreme interpretation of what this person said.

To give you an example, I'll show you what it looks like if I were to interpret your comment in the same way:

In some capacity, you have to admit, self sufficiency is possible. Forged metal, magnets, and batteries aren't necessary to sanitize water, grow, forage or hunt food, or to build shelter.

Hm.. well for example in the U.S. we have the Boy Scouts of America, this organization teaches boys and young men survival and general life skills. There's a spectrum of "off-grid" citizens. One one side of the spectrum, they still work and make under the table money, which in turn they use to buy some resources. On the other side of the spectrum there's citizens who have no communication with the general population. I guess the best way to see these examples would be on YouTube - searching for survivalist, off grid, and or self sufficiency.