The primary problem is the design. PERIOD
It’s fine when things are normal, deadly when they are not. It was not designed for fault tolerance. If AOA inputs are invalid, perhaps with IAS disagree, the initial procedures (pitch & power), coupled with unwanted nose down trim will naturally lead pilots to maintain proper pitch, speed increases, MCAS trim down more and on and on. Pilots hit Trim Cutout and are left with manual (slow) trim which becomes increasingly difficult to use as speed increases, until it becomes impossible. Can’t unload (nose down) at 1000 feet, and there’s too much nose down trim to control the airplane.