>and everyone else will poor and unemployed

How so? Everyone would still have their skills to provide goods and services and everyone would still have wants for other's goods and services, so an economy would still run. AI can shift the economy but it doesn't lock the entire population out of the economy. It can lock out any one group because everyone else gets the good/services of that group for cheaper from the AI, but if everyone else can't afford the AI, if the AI locks everyone out, then they trade between themselves instead. And that is the sort of 'worst case possible' outcome, not even what is likely to happen as the AI makes some things much cheaper.