FBW or manual control has nothing to do with these incidents.
If sensors/systems feed wrong information, to a pilot, an autopilot, an ADC, an MCAS, or whatever system, the aircraft is going down.
Some still don't get it.
The MCAS system was working PERFECTLY and did its JOB very PROUDLY and exactly "as designed to do so". .
But it got "WRONG INFORMATION" from the AOA sensors/system, and it was only fed by a single probe => That can be seen as a AOA signal concept error..