Most independent television stations had backwater news departments, if any. In fact, most unaffiliated stations usually counter-programmed something other than news to draw viewers who weren't interested. You'd get M*A*S*H instead of the local evening news. But some stations, especially in large cities, made an effort to program a later evening newscast one hour earlier than the network stations (that usually meant 10pm in the east and 9pm everywhere else in the country).
WPIX's news department created a network of independent stations and created their own ten o'clock national newscast under the banner of "Independent Network News." INN relied on WPIX crews for NY City footage (video material/stories), and local INN stations supplied some when news broke in their cities, and CNN provided much of the rest.
Newscasts in the 1970s and early 1980s were not as flashy as the ones we see today.