I mean, a bunch of his book is stoic epistemology, physics, and metaphysics, all of which is of dubious value. Anyone reading him is definitely going to be picking-and-choosing what they pay attention to, almost nobody today is going to go all-in on the entire edifice of the stoic system of philosophy, and nearly all readers are likely to disregard half or more of his book—as far as the pop-cultural life of the book, these large portions of it are practically invisible for a reason.

I do think it’s remarkable that there’s much salvageable at all in it, given the age of the work (though a fair amount of ancient philosophy remains relevant, or at least functions as good reading and exercises along the lines of koans for developing philosophical ways of thinking, an awful lot is effectively obsolete and only of historical interest) and that it came from one of the most powerful people on the planet. It’s not often you get something with much enduring value at all from someone who also happens to be at or near the pinnacle of human hierarchies of their day.

Though, in fairness, he’s mostly repackaging stuff he learned from others, it’s not exactly original thinking in the same way as the chain of works from Socrates-Plato-Aristotle, say.

Still, it’d be like, I dunno, Franklin Roosevelt penning a philosophically-inclined self-help book that was still widely read and referenced beyond the year 3,000 and in languages that didn’t exist when it was written. Pretty distinctive, very few works at all in that class, and almost none from the perspective of someone that highly placed politically, despite a strong bias in general toward works from the rich and powerful being created at all, and surviving. I’d say the only way it’s likely to permanently fade is if/when “western culture”, to perhaps include near-east and Maghreb Muslim culture, fades (there’s so much overlap of the parts people like, with forms of thinking from the East, that I expect it’d have trouble co-existing with them in the same body of thought, as an actively-read item of interest)