Sagan was a hero. It's difficult to underestimate his impact on science, not due to his work in science (he was probably too epic a stoner for that), but due to his work in science communication.

He changed the world. Before Sagan, science communication was for poor performers who didn't have anything productive to do with their time. After Sagan, science communication became a respected part of the role of a scientist. Nowdays many institutions have specific positions for the public understanding of science.

And prescient. His fears laid out in The Demon Haunted World, are playing out in the flat earthers, satanic panicers, anti-vaxers, and climate science deniers particularly in the USA, but also in the world.