If you think about it, that could be one way to extend the life of the universe. If you can run a simulated universe relatively quickly, for the people inside it would seem "normal" speed. So one day of running the simulation could be a hundred million years or some such number inside the simulation.
Then the simulated universe would reach the same point and develop their own simulation, which would run a hundred million years for one of their days. Compared to the original source universe, the second "pocket" simulation would run through its years in a small fraction of a day.
Continue the nesting of simulations, and all of a sudden you have entire universes and their timelines that are simulated in a fraction of an instant. That's a lot of extra time.
Perhaps we are one of the nested simulations, or perhaps we will be the original from which all the others will be based from. Maybe all the simulations are created in order to extend the time or provide a way to solve the last question.