I think the idea is rather silly. Look: we live one one little planet and right above us in the sky we can see that there are some 22 sextillion other planets,

I think the idea is rather silly. Look: we live one one little planet and right above us in the sky we can see that there are some 22 sextillion other planets, mostly empty gas giants. So if your question is “why are they simulating earth”, you’re way, way off base. What you need to explain is why someone is simulating 22 sextillion random gas giants. When you phrase it that way the question seems absurd. On the other hand, if you think only the earth is real or only you are real and the rest is being faked, then you’re engaging in the most self indulgent solipsism imaginable. If there is a god, for them to place 22 sextillion worlds full of nothing right where we can plainly see them, but never reach them, is a pretty damn effective way to say “you’re not that fucking important.”