Efficiency is paramount in an EV for range. Multiple motors is much more efficient than using a sort of transmission or extra driveshafts/differentials to transmit power. More spinning mass reduces efficiency any time the system is accelerated or decelerated. “Drivetrain losses”. Since batteries are expensive and range is important, it’s better to have a motor for each wheel or each pair of wheels. Gas motors and much larger and heavier making this very difficult so they use transfer cases and extra differentials and driveshafts to achieve 4wd or AWD