This Seattle Times article is quite informative: https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-73

This Seattle Times article is quite informative: https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/ https://www.seattletimes.com/business/boeing-aerospace/faile... It seems the MCAS had a flawed design where it would move the trim further than expected and would also trigger multiple times. Based on my understanding, the MCAS would have been quite safe if it didn't have these flaws (pilots deal with a failed AoA sensor as another case of "runaway trim").