'Avatar' is simple, it is simple scifi, Avatar = 'Smurfs' or 'Pocahontas' In Space but I think its 'world building' production and fx did have an impact. You don't need to go to far back even the 80s and 90s you see lame B-movies. Today people are investing big in scifi when they do it and you no longer have cardboard cut outs of some bridge on a spaceship or an Ed-Wood style set. Impact? The movie also help launch actors like Sam Worthington, Joel David Moore and others into mainstream that itself is 'impact', the recognition thing 'I know that girl' or 'I know that guy' and you check out the new movie because you know the actor from somewhere else. Avatar helped set off that whole 3-D thing maybe for the good, maybe for the bad, movies did it before Avatar but its mainstream because of Avatar...I can think of many big movies that had far less impact.