You are correct. But it's not 100% certain whether we would be capable of setting up a world simulation that would create intelligent agents of the human level. And much less certain, (1) are we able to set up such simulation in the next couple of centuries, and (2) will the simulation produce these intelligent agents after having been running for only a couple of centuries (wall clock time).
"Designing" isn't necessary for creating (OTOH, whether we can artificial select for it and avoid selecting for dead ends may be an issue.)