There's lots of potential for failure that the planes allow when flying. Some quick examples - they could have sensors around gas quality but do not - they rel

There's lots of potential for failure that the planes allow when flying. Some quick examples - they could have sensors around gas quality but do not - they rely on the folks providing the avgas to have good fuel. They could do built in weight and balance calcs with sensors - they do not, they rely on poor estimates for that. etc. Boeing in particular ALLOWS pilots to fly planes outside of most flight envelope limits. They do this in part because historically they didn't trust the computer as much and trusted pilots more. Airbus by contrast doesn't let you do this unless you take air data totally offline or something crazy to force alternative law. I suspect boeing will be moving towards the airbus model which is probably right. Airbus had arguably less local myopia when designing their planes - ie, future pilot populations come from a big group and making the plane as error proof as possible is best. Airbus had some issues around their automation without pilot override initially but I think those are resolved by now. If you want a scary video - check out this early A320 flying - first fly by wire / autothrottle: https://www.youtube.com/watch?v=YAg-WauGrLU https://www.youtube.com/watch?v=YAg-WauGrLU Can't have been a good feeling as that pilot. Note that the A320 is now considered a very safe plane. Aircraft have evolved from systems with almost no built in redundancy or safety. The design of the 737 is pretty old - 1967 or so. Let that sink in for a bit, consider what type of tech they had back in. This is not a 777 generation plane or even A320.