I agree on 90% of your post and detailed description.
However, on the conclusion, I am fairly convinced that the process is necessary but not enough to produce reliable system. I would say the most important parameter is "People".
If you have a team where people trust each other, where you can report odd issues without fear of reprisal, where people really want to deliver something safe, it will work, otherwise, with a dysfunctional team, using the exact same process, you'll get a terrible mess.
However, on the conclusion, I am fairly convinced that the process is necessary but not enough to produce reliable system. I would say the most important parameter is "People".
If you have a team where people trust each other, where you can report odd issues without fear of reprisal, where people really want to deliver something safe, it will work, otherwise, with a dysfunctional team, using the exact same process, you'll get a terrible mess.