If you've ever happened across a comic cover from the 1940s, you've undoubtedly seen (insert any superhero here) engaging in some fisticuffs with Nazis and racist caricatures of Japanese people. Even though comics from the 40s haven't aged well as far as content is concerned, they've fared incredibly well regarding their price tag in the resell market. So even though the comic industry would like to forget about the jingoistic narratives that power those tales, the rarity of comics from the 40s make moving on slightly impossible.
To be fair, comics- and specifically the superhero genre- didn't stop being propaganda after WW2. The Fantastic Four famously gained their powers while attempting to "beat the Reds in the space race." However, no era of comic propaganda is as fascinating as the 40s. In the video linked above, the YouTube channel Comic Tropes explains how WW2 helped fuel the superhero boom in the 40s.