The biggest cultural impact from the Avatar movies is on the technology developed that will be used for other movies. The stories, characters and even world-building are not all that great, however the film-making is astounding and will reverberate through the industry for decades.
This is because the tech is no longer revolutionary. Everything used and displayed on the first Avatar was a first time or completely new and bespoke piece of tech that had some visual impact apparent for the audience. Everything on the second one is been done on better films before or if it's brand new equipment or technique, is something that is not discernible by the audience through the screen. Also, nothing of importance or substance regarding the plot happens in any of the 3 hours of script. Perhaps the most boring film I watched in 2023.