Leftists are crying because the obvious industry plant, Witch Hat Atelier, isn't nearly as popular as Frieren. The author, Kamome Shirahama, is a leftist with pro-Palestine views, drawing a character in the same pose as Handala, which was a pro-Palestine cartoon character. She has also donated to "gaza related" causes, used hashtags in support of Gaza, and signed various petitions and shared news related to it. She is also pro LGBTQ, and the series explicitly contains same-sex relationships because she intentionally added them for solidarity with the "pride movement". The story also contains themes related to inclusiveness and diversity, and she has said that she used the diversity in american media as an inspiration... She is also connected to UNESCO, with her interview with Laetitia Kaci, promoting the idea that the story is for global audiences, and Kodansha promoted it as an international feature piece. Most Manga/Anime readers are not interested in stories with artificial ideological pandering, and would prefer stories like Frieren that don't have that loaded baggage... especially these days as more fans have become very wary of anything that even smells like woke garbage.