You’re right to say that “good enough works”, but IMO wrong to use this as a criticism of the parent posts which did a good job of explaining why it’s best practice to avoid RGB in this context of image processing (vs YUV for example, which is incredibly easy to implement in a few dozen lines of code). Context is important, and we are discussing a situation in which RGB is demonstrably insufficient.

Even beyond that though, there is something to be said for seeking to approach perfection. Nobody is requiring or expecting perfection, but when someone offers an easy way to get closer to it, it will rub many the wrong way when someone rebukes the helpful suggestion with the excuse of “good enough is fine, so stop providing helpful product improvement advise!” This is how you achieve mediocrity.