I think the word "War" is a major deterrent for moviegoers, even for fans of the first 2.
Rise is about escape and Dawn is about struggle. War implies active participation in aggressive
behaviour. Nobody likes a warring ape clan, Dawn is against that idea. And War against humans,
even though it is "bad" humans, make for a rather dark & depressing story for GA and casual fans
looking for fun & lighter fares.