You are wrong in the general case—quantum systems cannot are are not routinely simulated with non-quantum computers.
Of course, since all of the world is quantum, you are right that many systems can be simulated classically (e.g. classical computers are technically “quantum” because the entire world is technically quantum). But on the nano level, the quantum effects do tend to dominate.
IIRC some well-known examples where we don’t know how to simulate anything (due to quantum effects) are the search for a better catalyst in nitrogen fixation and the search for room-temperature superconductors. For both of these, humanity has basically gone “welp, these are quantum effects, I guess we’re just trying random chemicals now”. I think that’s also the basic story for the design of efficient photovoltaic cells.
You are wrong in the general case—quantum systems cannot are are not routinely simulated with non-quantum computers.
Of course, since all of the world is quantum, you are right that many systems can be simulated classically (e.g. classical computers are technically “quantum” because the entire world is technically quantum). But on the nano level, the quantum effects do tend to dominate.
IIRC some well-known examples where we don’t know how to simulate anything (due to quantum effects) are the search for a better catalyst in nitrogen fixation and the search for room-temperature superconductors. For both of these, humanity has basically gone “welp, these are quantum effects, I guess we’re just trying random chemicals now”. I think that’s also the basic story for the design of efficient photovoltaic cells.