> Proponents of self-sustainment as the way forward advocate off-grid lifestyle that provides energy and large amount of food/materials internally / within family or homestead. A house and a plot of land, and some fruit/veggies/animals, with solar or geothermal, etc.
Yes but this isn't possible with current population levels so it's a non-started from a practical standpoint. It also has downsides as you can't build things like hospitals or universities, particle colliders, or hardware/electronics to do self-sustainment. All and I mean all who advocate for this specific way of life only do so and are able to do so because it's subsidized by technological innovation throughout the rest of the world. To be clear I support people doing this. I think it’s really cool and good for society, but it’s important to be aware of how you’re actually able to do it.
> In my mind then, a 5,000 people town is as much on the other side of the spectrum from that, as a 5,000,000 people town.
I think this would be a great opportunity to recalibrate, because those are not even remotely the same thing in any way, shape, or form. Even ancient peoples who were undoubtedly more self-sustaining than anyone who exists today had settlements larger than 5,000 people.
> In fact, in North America, small and medium towns in my experience (Minnesota, Manitoba, Ontario) are quaint and lovely, but worst possible compromise - no self-sustaining benefits of independent homestead, but with limited to no public transit, no high density dwelling, spread out infrastructure. You cannot live without a car in a small north american town - modern or old. They are beautiful lovely historic worst parts of sub-urban without the urban/core.
I agree that this is the experience but you need to look to Europe for better examples. I'm also advocating for things like train service, majority of your experience being walking or biking (i.e. a 15-minute town), and very reduced car ownership. Having a car isn't that bad, it's having 2 or 4 cars and using them for everything under the sun. Europeans have cars, and they also have infrastructure, and farms, and self-sustaining areas. It's a great blueprint to improve upon. I'm not advocating for what is, but what could be.