TLDR: Statists measure success based on the state, so in order to convince them that anarchism us successful we would need to stop being anarchists.
"For anarchists who do know something about anthropology, the arguments are all too familiar. A typical exchange goes something like this:
Skeptic: Well, I might take this whole anarchism idea more seriously if you could give me some reason to think it would work. Can you name me a single viable example of a society which has existed without a government?
Anarchist: Sure. There have been thousands. I could name a dozen just off the top of my head: the Bororo, the Baining, the Onondaga, the Wintu, the Ema, the Tallensi, the Vezo…
Skeptic: But those are all a bunch of primitives! I’m talking about anarchism in a modern, technological society.
Anarchist: Okay, then. There have been all sorts of successful experiments: experiments with worker’s self-management, like Mondragon; economic projects based on the idea of the gift economy, like Linux; all sorts of political organizations based on consensus and direct democracy…
Skeptic: Sure, sure, but these are small, isolated examples. I’m talking about whole societies.
Anarchist: Well, it’s not like people haven’t tried. Look at the Paris Commune, the revolution in Republican Spain…
Skeptic: Yeah, and look what happened to those guys! They all got killed!
The dice are loaded. You can’t win. Because when the skeptic says “society,” what he really means is “state,” even “nation-state.” Since no one is going to produce an example of an anarchist state—that would be a contradiction in terms—what we’re really being asked for is an example of a modern nation-state with the government somehow plucked away: a situation in which the government of Canada, to take a random example, has been overthrown, or for some reason abolished itself, and no new one has taken its place but instead all former Canadian citizens begin to organize themselves into libertarian collectives. Obviously this would never be allowed to happen. In the past, whenever it even looked like it might—here, the Paris commune and Spanish civil war are excellent examples—the politicians running pretty much every state in the vicinity have been willing to put their differences on hold until those trying to bring such a situation about had been rounded up and shot."
In more practical terms, a society, anarchist or statist, that doesn’t have the means to launch ICBMs at the capital city of nuclear powers is destined to be walked all over by those nuclear powers. We saw this in real life with Venezuela and are seeing it right now with Iran. If Venezuela or Iran have the ability to glass Washington DC with nukes, Maduro would still be in Venezuela and Khamenei would still be alive. Just from reading about how those nuclear powers became nuclear powers, I do not see an anarchist society having the ability to acquire nuclear ICBMs without either reorganizing their society into a non-anarchic one or submitting to one of the nuclear powers for protection under a nuclear umbrella like what Belarus has done towards Russia. A PM of Pakistan said that they would rather eat grass if it means they could get nukes as protection against India. This is completely anathema to an anarchist society because that PM was more or less saying that Pakistanis starving from malnutrition was well worth the human cost for getting nukes as soon as possible, but in the end, Pakistan did get nukes (with the help of China depending on who you ask). If Pakistan didn’t rush to get nukes, I’m not even sure if Pakistan would still exist today since Pakistan’s military is completely outgunned by India’s military and the stretch of land between Pakistan’s capital and the Pakistani-Indian border is completely flat.