Appreciate the write up, starting with ‘why’ is always good. Few will disagree with that.
Design however, is very much an iterative process — and each cycle you should be prioritising and honing your design decisions to best answer your why question.
The iterative design process isn’t the problem, that’s the execution aspect. Not having the right design brief, not asking the right questions and not having the right starting point — will indeed be problematic, you could have the best team and execute flawlessly on a bad idea or brief (many of which you listed).
Even with the evolution analogy — lifeforms go through “iterative revisions” over countless life times and often becomes something so wonderful people continue to argue today over evolution verses intelligent design.