Some planes fly 3-4 times each day. Each time, they carry ~150-200 people. They are incredibly mechanically, electronically and software -wise complex machines,

Some planes fly 3-4 times each day. Each time, they carry ~150-200 people. They are incredibly mechanically, electronically and software -wise complex machines, and fly under huge range of conditions (number of conditions and range of values for each), withstanding elements, forces of physics, material exertion / fatigue etc etc. So if there's an airplane manufacturer, delivering hundreds of planes to airlines, where processes allow for something like this to happen to a plane, and it's confirmed that it wasn't a single exception, it really brings to question how many out of tens of thousands of parts/aspects of those planes do not meet the expected parameters/standards and how many disasters are waiting to happen.