Adding grain is a great way to uniformly mask out whatever imperfections that couldn't be edited out. I would do that if I felt lazy and don't want to spend al

Adding grain is a great way to uniformly mask out whatever imperfections that couldn't be edited out. I would do that if I felt lazy and don't want to spend all the time removing dust from my photos. But even then, I would only add grain via some filter that has a "grain" parameter built in. I suspect adding just grain without other effects to go with it would not be an improvement in general.