I see anarcho-primitivism as a set of critiques, not a program. Others will differ depending on who you ask, but I have no interest in "bringing everyone back to 10,000 BC", since such a thing is impossible, even if the majority of the world's population were what we now call 'primitive'. I see familiarizing oneself with the skills and techniques of HG lifeways as something that might help people in the near future, when industrial civilization finalizes its current catabolic collapse through the peaking and disappearance of the resources it needs to survive (oil, rare earth metals, and mineral fertilizers that modern agriculture depends on). Climate change will likely make many places unviable for reliant farming, with higher CO2 levels increasing fungal infestations and the regularity of droughts, flash floods, and extreme temperature variations. The remaining HG societies of today exist in regions where agriculture is impossible (the Kalahari Desert, much of the Outback, the inner Amazon rainforest), so I see that as a way in which humans could cling onto survival in a harsher future.
To be honest, I'm terrible at giving cogent answers via text, but this is the best I've got. Since collapse itself (not the sudden Hollywood millenarian cataclysms most people envision, but a centuries-long process of gradual breakdown) will likely start affecting the world population's ability to ignore the global human carrying capacity by the mid-century, I kind of see the issue of supporting billions of people as a self-correcting problem. I know that this seems like a horrifying thing to consider, the bluntness of it all. When I say that the population will begin to taper off, I mean to say that the death rate may return to pre-industrial levels, not the same as if everyone dropped dead after a asteroid hit the planet or something. The actual sustainable human population without fossil fuel-supported agriculture is somewhere between 500 million to 2 billion people, depending on who you ask. Most people who end up living in a post-collapse world will have to deal with the increased effects of climate change, ecosystems that have fallen apart after the current mass extinction ceases, and many other ghastly scars of industrialism. Most will try their hands at farming or herding animals in the places where such practices still remain viable, there might even be little startup civilizations in the Arctic archipelago or Iceland, if things stabilize to temperate there. And most certainly won't be hunter gatherers. All I see it as is a viable lifeway for surviving in a harsher world, considering how ideal Sahlins' insights on the !Kung bushmen were.
If I could live in some sort of band society with like-minded people, I wouldn't really give much of a shit about civilization if I could actually get away from it. That's next to impossible in today's world of expanding infrastructure and surveillance, however. Let's say that my group is living in a rare sliver of the Tongass Archipelago, 400 years in the future. Aside from the fledgling city-state of Anchorage or a distant empire at that inhabits the throat of the Mackenzie delta, there aren't too many civilizations around to bother us. We also happen to inhabit one of the last salmon-bearing rivers in the Pacific Northwest, a river that is integral to our cultural identities and subsistence as people. We also aren't purists, so let's say that my group also has a mixed economy, where we hunt animals and culturally modify plant species we depend on, not clearing forests for farms but also not having absolutely no influence on our foodweb either.
Say that a freighter from Anchorage comes to our watershed, and tries to buy our lands, even though we don't practice their system of private property or the atomized ownership of lands. They want to build a dam, one that would kill off the salmon only so that they could generate hydroelectricity back at home. If they directly threatened our survival, I would fight them to my dying breath, no more, no less.
Others with an anti-civ viewpoint probably could argue different views, some more jingoistic, some more focused on more communication between both potential parties. But honestly, that's my stance. If my preferred life was lived without the interference of the civilized, of their constant intrusions, then I'd be all the happier to camp in the hills and let them rot in the cities. I have no association to a nation, to a mass of strangers that I'll never know or care about. I can sympathize with a stranger, but can rarely empathize with one until I get to know them as a person, until we have some sort of reciprocal relationship established.
So I kind of see my view as this: one of simultaneous separation and defense. If you're interested in getting a far more nuanced version of this view, I'd recommend reading an essay by a writer under the alias of "Seaweed", titled *Land and Freedom". There are fragments of it on the Anarchist Library webpage, but you might be able to find the full text on some zine site.