you make a fine point nonetheless i'm going to act as if it wasn't a rhetorical question and attempt to answer how we can train ai to plan the economy when we feed it erroneous models.
by presenting it with as many models as possible especially erroneous ones. and giving it a testing ground to trial and error all of them. you create a game like sim city and have the ai play a thousand games at once at accelerated time frames so it simulates all models over decades with countless variables millions of times.
then you graduate it to in economies of video games, not for the economic realism of video game models, but for the real and unpredictable human input of player driven economies, either have the ai operating as npcs, or perhaps its a crypto p2e game and the ai is concealed behind thousands of fake users and it has a prominent voting share of multiple competing decentralized autonomous organizations it can use to shape policies in game that keep the economy healthy for as many players as possible. without anyone even knowing it was there. some future videogame
and then graduate it to test its powers on a small town. as a tool used by local government to suggest policy, nobody even needs to know its there. if you can get that to go smoothly graduate it to a city, then a state, then a country.
we can tell that hasn't been tried yet since the economy seems kinda retarded