Short answer: “majority” is hyperbolic, sure. But it is an elite conviction espoused by leading lights like Nick Beckstead. You say the math is “basically always” based on flesh and blood humans but when the exception is the ur-texts of the philosophy, counting statistics may be insufficient. You can’t really get more inner sanctum than Beckstead.

Hell, even 80000 hours (an org meant to be a legible and appealing gateway to EA) has openly grappled with whether global health should be deprioritized in favor of so-called suffering-risks, exemplified by that episode of Black Mirror where Don Draper indefinitely tortures a digital clone of a woman into subjugation. I can’t find the original post, formerly linked to from their home page, but they do still link to this talk presenting that original scenario as a grave issue demanding present-day attention.

less than 1%…on other long-term…which presumably includes simulated humans.

Oh it’s way more than this. The linked stats are already way out of date, but even in 2019 you can see existential risk rapidly accelerating as a cause, and as you admit much moreso with the hardcore EA set.

As for what simulated humans have to do with existential risk, you have to look to their utility functions: they explicitly weigh the future pleasure of these now-hypothetical simulations as outweighing the suffering of any and all present or future flesh bags.

Perhaps present-day humans are more obviously aided by questioning literally any aspect of hyper-capital. Better to cast out to the far future and insist (without any real basis) that fellating billionaires is the best course.