IMHO, processes have to be documented in such a way that we can see and figure out where we can improve. It does not have to be because ISO require or don't require. We have to document good business practices.
Also, it helps when new hires come onboard, they can refer to the written procedure. I don't quite understand why you said my points are apropos. Anyway, those are just my humble opinion, that is how I forsee it. Things will become messy and chaotic if procedures are not written. There is no way you can validate if people are doing it right or wrong.