Right - fix the economy instead. Why should increasing efficiency cause people to have less resources - that makes no sense.
Banning AI does increase efficiency. It makes it more efficient for a working class family to afford to survive. What perverted definition of the word were you considering?
Because there are people who live off rent (in a broad sense of this world), and there are people who live off selling their ability to work. Increased efficiency and productivity may or may not benefit the second kind of people, depending on whether they can sell their labour to be used for something else.