Using that standard, does anything matter? But that's not why they do it. It's a service they provide to their affiliates, who build their own local news around it. Year after year, the affiliates are asked, and they continue to want it. Competitively, CBS has to offer an evening news and a morning show for that reason. Neither are necessary for the viewers. The viewers have their favorites, and their regular routines. But if you're going to be a traditional TV network (not Fox or CW), this is what you do. Otherwise, might as well shut the whole thing down. But the issue for this particular thread is the specific people in the specific roles, and apparently those are about to change.