For years, CAFE regulations have meant that manufacturers must meet minimum fleet fuel economy averages or else pay fines. In order to sell more profitable but less fuel-efficient F-150s, Ford also needed to sell little Fiestas or Focuses. In order to sell Suburbans, Chevy also needed to sell Cavaliers or Sonics. But now that Ford can sell Mustang Mach-Es and Chevy can sell Blazer EVs for 50 or 60 grand AND get credit for something like 100 MPG equivalent, there's no longer any incentive for them to spend huge sums developing cheap cars that will net tiny profits (if any).