> because there can't be multiple advanced civilizations because as soon as we suck-up all the available computation the simulation speed crawl to a stop.

If our reality is a simulation. It doesn’t matter how fast the “computer” is running. We could be living inside a grid of rocks in a gigantic dessert being pushed around slowly by an immortal turtle according to rule 30. How would it matter for us as we are living in the simulation and our relative time is always one second second per second, even if it takes a billion years for the turtle to rearrange the rocks to compute that second.

So there is no way to “drain the simulation of resources”, unless we figure out a way to kill the turtle, but that’s not likely to be possible, since we’re just patterns in the rocks.