True, but the peak of success was in the 60s, with good presence in the 70s and particularly in the 50s. The superhero genre began having a remarkable presence during the 00s, and achieved throughout our current decade the highest peak of popularity (The Avengers being the most successful one in box office numbers back in 2012). Even so, no new movie in the genre managed to top The Avengers ever since, and the only one I see has a concrete possibility is Infinity War. In the next decade, will the audience level substantially drop? Nobody says that the genre will be extinguished by then, but who knows if it will maintain its popularity...