If you had access to a scifi-level artificial super intelligence that could simulate anything perfectly at unimaginable speeds, what experiments would you want to run that would be unethical otherwise
If everything is perfectly simulated, the rules that allow consciousness to emerge are also there, and thus consciousness would emerge, regardless of whether it's a simulation or reality. If we only simulate a consciousness without laws of reality, that consciousness would still be designed to mimic a consciousness from a reality with laws (ours), and since it would be a perfect simulation (and it would have to be so in order to run meaningful tests), that consciousness might as well be as real as us. Thus, unethical.