> ...security of places
sustainable?
I think you nailed it on the essential desire. But...
There's gonna be death and taxes in one form or another wherever you go, whatever you get into. If you want your garden to be good it's going to take regular input - essentially forever. (Food forest? That's going to take regular work too.) I think it's more about what's acceptable to a person when it comes to what is required to keep something (their property?) going.
If by "sustainable" you mean that one is OK with the required input/maintenance (all the moneys, duties, dealings, etc that go with property) - well, like much else, "that depends" <g> more on the person you ask rather than on the rules of property. What dues/taxes/duties/inputs/effort do people here find acceptable to maintain their good life? When/what makes something become "unsustainable"?
"Property" is out there for us to use if we have the resources. It has a long track record, is fairly easy to understand the rules and people seem willing, mostly, to abide the rules. It has a lot going for it, more than most other "security of place" options. The big drawback is cost and the required perseverance, discipline and strength. Many have the first, far fewer the other.
Given an acceptable definition of "sustainable", maybe an interesting direction/question would be what other options does a person in the Western world have for security of place needs besides property. I guess you could point to intentional communities but to my mind they are FAR riskier than simple property ownership. There are probably other options though...
Rufus