Right now, the vast majority of games have characters with fixed walk cycles that are used no matter the terrain. Realistic CG needs to have a walk cycle that captures the subtle changes in gait that corresponds to a given surface. I know people have been doing research on adaptive walk cycle, but afaik it has yet to hit production games.
For generating art, there is hope, as procedurally generated games look fantastic (No Man's Sky), but have yet to expand beyond sci-fi games, or into games with story and specific art styles.
Maybe reusing assets is the way forward, but I'm skeptical. Reusing the visuals just means more army guys fighting in sandy deserts crouching behind crates. Maybe the Storm Trooper models for battlefront really are as good as they get. But even then, I think aesthetically realism can lead to a dead end. The most visually impressive game I've played, other than Star Wars Battlefront is The Witness, which is simple in the CG sense, but has some really tremendous visual aesthetic moments that are something I've never seen done in a game. For me, the stylized look and the artistic/game opportunities that enabled were far more exciting than Battlefront's perfect rocks.