Consider a very fast classical computer is simulating a universe with newtonian physics. There's no concept of quantum mechanics in this universe. You create a black box where people in this simulation can ask you questions. You also have a quantum computer. Now you can answer questions that require quantum computing which they cannot answer in their universe

Next step: we're a simulation in a universe which has ways to violate complexity bounds we hit with quantum computers

You tell me: why would it? And if it could, why can't we build similar machines?