I have had this problem (runaway trim) and it was difficult to fly the airplane but I am still here so it was not impossible. I did not give up and flew the airplane to the ground with full nose down trim and because of a broken trim cable, no way to reverse the problem. I also flew the 737 for thousands of hours (although never had the trim runaway on that aircraft). I am not an "armchair" pilot and I do know how to fly and how to perform an emergency checklist. I am appalled at the lack of professionalism shown by the pilots in the two 737Max aircraft and even more appalled at the way so many on this thread are preferring to blame Boeing rather than the real cause of the tragedies because of political correctness. If they get their way they would put Boeing out of business and who would benefit then?
No aircraft is immune from failures of some type, and it is the pilot's job to fly it nevertheless and to keep the people who are placing their trust in him/her safe by at the least maintaining an average level of skill and knowledge. Which is all it takes. You don't have to be a super hero.
Fix the real problem. The human element. Take it as a warning of what will happen if we continue to dumb down (to the lowest common denominator as has been suggested we should be doing). Maybe we should be replacing the pilots with computers. They could not do any worse.