Good points indeed. I think you can even further say that people will just make mistakes regardless of the process. If engineers take too long to deliver it’s “over-engineering” or if the deliverable fails at any point the engineers “didn’t know what they were doing”— if requirements change suddenly along with deadlines it’s “mismanagement”. I’m not saying these are not real problems, it’s more that they’re inevitabilities and the processes we come up are just to mitigate them, not eliminate them entirely.