Mathematically, it's more likely we're living inside some sort of "life simulation" than real life. To give a scenerio: future-humans currently live in the real world, and they want to find out how their ancestors lives were like. They create an extremely complex program (this program actually produces real, living organisms for maximum accuracy), and this program let's them carry out tests in that world. Let's say they make 15 different programs to somehow calculate some sort of an "average" as to how past-human behavior was. Well, there's 15 simulations, but there's only 1 reality meaning it's mathematically more possible we're in a simulation rather than real-life (though it's still 50-50 that future-humans don't/do currently exist, and there's a probability of 1/3 that, if they do exist, they decided to create this type of program)

EDIT: I didn't read the entire thread yet. Sorry if someone already posted this. It's from an essay. I didn't develop this theory.