Long over water flights used to be three or four engines. (I've flown both) They didn't go to two engines because it was SAFER. They did it because it was CHEAPER. Profit is EVERYTHING.
Not enough motors. If that had happened at 30 west or half way between SFO and HNL, you are now single engine, you are flying lower and slower, the water is real cold and the fish are bigger than you are. They didn't go from 4 motors to 2 for long distances because it was safer.
I would imagine they would cruise that airplane at somewhere above FL 500 or higher? Concord flew for awhile at FL600. What happens to everyone during a rapid decompression at 60 thousand feet? Just a thought.
Of course some are more at risk than others. Some live through the virus with little symptoms, some die from it. Everyone reacts to the virus differently. However the means of transmission are the same for everyone. You may have the virus and be a-symptomatic but You can pass it on to someone who will get very sick and possibly die. I will gladly wear a mask, maintain proper distance etc. if it means not spreading a virus that has already killed over 400,000 people in this country and many hundreds of thousands around the world.
Compare the original 737 with the 737 Max. No comparison but differences training is a lot cheaper than having to acquire a whole new type rating. It's all about the $$$.