Its just not even close to being realistic across any culture or long lived society throughout our entire history.

I largely agree.

My reading is that the book isn't meant to depict a realistic scenario (all major characters are caricatures), but instead show a stark contrast between Ayn Rand's ideology and socialism to inform what the ideology is and is not. That's why Galt is so opposed to charity, not because that's a reasonable take, but because he's a caricature of the ideology (surely giving for your own pleasure is consistent with Objectivism). The point isn't to say we should all be like Galt or that society is currently as it's presented, the point is to create a context to highlight the practical differences.

Can you point to one place in human history that this has ever worked long term?

That depends on where you place the goal posts. If we're talking about literally replicating Atlas Shrugged (i.e. an anarcho-capitalist "state"), then not even your example qualifies, as that's just an example of a bunch of egotistical idiots halfway implementing a poorly thought-out plan.

But if we're talking more generally, then the US is a good example. People fled to the New World to escape oppression from Great Britain and built a life for themselves, and we call that "The American Experiment." If we placed the founders into a political ideology today, it would probably be some brand of libertarianism (many of whom call themselves "Classical Liberals" to this day, which the founders absolutely are). But they absolutely saw the need for some sort of governing body with a monopoly on force, they just wanted that governing body to be small and largely get out of the way.

That said, objectivists aren't libertarian, nor are libertarians objectivist, and Ayn Rand famously hated libertarians (you can read through this if you like). I claim to be a libertarian, and I find Ayn Rand specifically and objectivists generally to be insufferable, and here's one quote from that article to hint as to why:

Jennifer Burns notes how Rand's position that "Native Americans were savages" and that as a result "European colonists had a right to seize their land because native tribes did not recognize individual rights" was one of the views that "particularly outraged libertarians".

That said, I find some value in Rand's work, at least in terms of pointing out a direction that might be valuable to explore. We definitely don't want our systems getting in the way of innovation, and I argue our systems should support innovation, which is why I'm a fan of safety net systems like UBI/NIT (which Rand would hate, but she also lived on Social Security, so what does she know...).