Scott Aaronson wrote a bit about the following thought [0]. If copying a brain and simulating reality ala The Matrix is possible at all, then if you get your brain copied you live one biological live but your copies have an unbounded number of existences (millions? billions? trillions?)

So, if copying brains is possible, and you don't know which version of you you are, you might have odds of, say, 1 to 1 trillion to be living your first, biological live.

Which is to say, if copying brains is possible, you are likely to be running in a simulation already.

[0] there's multiple links and I can't find where I first read, but I found this one from 2024, https://scottaaronson.blog/?p=7774 and uhh.. turns out the argument isn't from him personally (and he doesn't even believe on it), and is best presented here https://simulation-argument.com/ (though it's presented very differently so idk)