3-D has been a gimmick at least since Friday the 13th part 3
If the MCU hadn't been "impactful to the world of film making" then everybody wouldn't be trying to make cinematic universes, and if Avatar had been then people wouldn't have stopped talking about it nearly immediately after it came out.What Cameron has achieved with 3 point turning films in cinema (Terminator 1-2, Titanic and Avatar) has been far more impactful to the world of film making than all the 27 MCU films Feige has produced. Feige movies are popcorn fun produced by a well oiled cooperate machine as Disney. Cameroon's movies are personal art.
Seriously, the only time people talk about Avatar these days is to marvel at how much it's dropped off of the cultural landscape. Four sequels that keep getting pushed back and a portion of Walt Disney World is pretty much all the impact we can see.