the idea that the best narrative is the one that thrives

I was pretty clear that the effectiveness of a narrative is dependant on the results you're seeking. I think you can turn a narrative loose into the world and it will run autonomously to a degree, and you could use a story's ability to thrive and survive as a measure of at least how attractive and engaging it is, but no, I don't think that is what makes a story effective for the purposes of influencing a large amount of people to make better choices, to have more curiosity, to think more about things they don't normally think about.

Social engineering like this does take deliberate work. It takes effort and work to keep a story alive and growing. The problem is we already have tons of people doing this work for their own agendas. Sometimes they're good stories, sometimes they're terrible stories, but it almost doesn't matter the "quality" of the narrative, since our brains are designed to hook into narratives to explain the world even if the explanation doesn't even make a lick of sense. See: anti-vax doctors and flat earthers.

Can you give examples of what you think might be working stories?

It's really hard to create a narrative with the sheer power and influence of stories using fear and hate, because we all respond much stronger to fear and anger than we do more abstract ideas like charity and empathy as a matter of survival. I genuinely have no idea how you fight this. It's literally an exploitation of all of our survival responses and it will always work on some segment of any given population, and once it starts to work on a few people, the effect will snowball. My prescription here is that we can't let hate speech start in the first place. We have held the sanctity of bad ideas in too much regard for too long, other nations don't fuck around with this shit because they know how contagious hate and fear is.

There is however one great example of successful, working populism I can think of though, and that's Bernie Sanders. He's been effective in messaging to both right and left for decades because he's consistent, he validates our problems and keeps his focus laser-tight and narrow on one talking point: which is how the wealthy oligarchs are hoarding our wealth. That's all, and he's held the same talking point for decades and it works on both sides of the political spectrum. It's just a shame that we're in a place where power has already been ceded to the corporate interests and people like Bernie are muzzled long before they get real power.