Our point-estimate best model plausibly says so, but, structural uncertainty? (It's not privileging the non-simulation hypothesis to say that structural uncertainty should lower this probability, or is it?)

That is a good question. I feel like asking 'in what direction would structural uncertainty likely bend my thoughts?' leads me to think, from past trends, 'towards the world being bigger, weirder, and more complex than I'd reckoned'. This seems to push higher than 99.5%. If you keep piling on structural uncertainty, like if a lot of things I've learned since becoming a rationalist and hanging out at SIAI become unlearned, then this trend might be changed to a more scientific trend of 'towards the world being bigger, less weird, and simpler than I'd reckoned'. This would push towards lower than 99.5%.

What are your thoughts? I realize that probabilities aren't meaningful here, but they're worth naively talking about, I think. Before you consider what you can do decision theoretically you have to think about how much of you is in the hands of someone else, and what their goals might be, and whether or not you can go meta by appeasing those goals instead of your own and the like. (This is getting vaguely crazy, but I don't think that the craziness has warped my thinking too much.) Thus thinking about 'how much measure do I actually affect with these actions' is worth considering.

Our point-estimate best model plausibly says so, but, structural uncertainty? (It's not privileging the non-simulation hypothesis to say that structural uncertainty should lower this probability, or is it?)

That's a good question. My impression is that it is somewhat. But in the figures we are giving here we seem to be trying to convey two distinct concepts (not just likelyhoods).