"ISO noise" is a thing I've heard on a few different film sets and it's a convenient shorthand for "the noise that becomes really apparent only when you crank up the gain". Now that I'm thinking about it, there's a good chance this is more of a thing where I'm from, since our native language doesn't have different words for grain and noise, so we have to diffentiate between them with a suffix, which we then incorrectly also use in English. I guess on a film set with mostly native English speakers, noise and grain is clear enough.
Next, no shit aesthetics are subjective, I never said this is the one objective truth. I said this is a thing that many people believe, as evidenced by the plethora of resources talking about the difference between noise and grain, why tasteful grain is better than a completely clean image and how to add it in post.
And finally, come on, it's obvious to everyone in this thread that I'm referring to digital, which is also not "just a subset" it's by far the biggest subset.
So idk what your point is. Most things are shot digitally. Most camera companies try to reduce sensor noise. Most camera departments try to stick to the optimal ISO for their sensor, both for dynamic range and for noise reasons, adjusting exposure with other means. In my experience, most people don't like the look of sensor/gain/iso/whatever noise. Many cinematographers and directors like the look of film grain and so they often ask for it to be added in post.
Besides the many/most/some qualifiers possibly not matching with how you percieve this (which is normal, we're all different, watch different content, work in different circles...), where exactly am I wrong?