I think Attack on Titan and Demon Slayer have quite a lot in common

‌Today, I finished my very first binge-watch of Attack on Titan.
It took me about 3 weeks to watch it all. Watching it until the end really gave me a lot to think about.
Around this time last year, I finished binge-watching the Demon Slayer anime, and as someone who has seen both, I feel there are quite a lot of similarities.
Attack on Titan, the hit representing the 2010s, and Demon Slayer, the hit representing the 2020s.
Commonalities:
The main plot involves killing man-eating creatures (Titans/Demons) that appear in the titles.
From the first episode, the protagonist's mother is killed by a man-eating creature.
Consequently, the protagonist leaves home and joins a group that is somewhat like a child soldier organization, dreaming of revenge against the man-eating creatures.
Like a true protagonist, they awaken specific abilities while fighting the man-eating creatures.
Regular humans also use the power of the man-eating creatures to fight (in Demon Slayer, Nezuko and Genya are somewhat similar).
To kill the man-eating creatures, you must aim for the back of the neck with a blade (in Attack on Titan, they can be killed in other ways as the story progresses into Part 2).
In fact, the man-eating creatures are actually humans who have transformed.
Even if they have tragic backstories, the man-eating creatures must be killed regardless.
People who awaken specific abilities face a limited lifespan (in Attack on Titan, Titan shifters have a 13-year limit; in Demon Slayer, the Mark has a 25-year limit).
The author's drawing skills are somewhat lacking, so they rely heavily on the animation quality.
Both are rated 19+ and are quite gruesome with many scenes of bodily mutilation.
Events from thousands of years ago affect the current timeline of the story.
The protagonist's father is a very important figure who knows about the protagonist's power and triggers their awakening.
There is a mysterious space where characters are pulled to in the final stages? (The Coordinate/Infinity Castle).
The civilization is underdeveloped compared to the era of the story (Paradis in Attack on Titan is at a pre-modern level unlike Marley, and even though Demon Slayer is set in the modernizing Taisho era, the setting and tools don't feel like the 20th century).
The protagonist is not the most popular character; instead, a man with a chic image is the most popular (Giyu or Levi?).
Is the protagonist the final boss? (Eren definitely is, but Tanjiro almost became the final boss, though he didn't fight properly and returned to being human, so it's debatable).
The final scene ends in the distant future. However, the atmosphere is completely opposite.
Spin-off manga covering the characters' school lives were released (Attack on Titan: Junior High and Demon Slayer Academy).
Both have faced right-wing controversies? (Though this might be unfair criticism).
When the Attack on Titan anime came out in 2013 and the first season of Demon Slayer in 2019, they were a syndrome-level phenomenon, popular not just in Japan but also in Korea. Even I, who didn't watch much anime back then, had heard of them.
The first season openings start with "Guren" (or similar iconic tracks), and both are famous for having legendary hit anime theme songs.
The TV series were produced up to 4 seasons (Attack on Titan released Season 3 in 2 cours and Season 4 in 3 parts, while Demon Slayer has 4 TV seasons plus 4 movies).
The final arcs were produced as movies (The Demon Slayer finale is still unreleased. The Attack on Titan finale movies were essentially compilations).
There was some controversy regarding the original manga's ending, but it subsided as additional content was added to the tankobon volumes, and later, as other manga endings were worse, it received a re-evaluation. Attack on Titan was reinforced in the anime, and the anime finale received overwhelming praise; I hope the Demon Slayer anime also concludes with applause.
Voice actors like Yuki Kaji (Eren/Sabito), Natsuki Hanae (Tanjiro/Colt), Hiro Shimono (Connie/Zenitsu), Yoshimasa Hosoya (Reiner/Kaigaku), and Takehito Koyasu (Zeke/Hand Demon) appeared in both Demon Slayer and Attack on Titan.
Of course, there are differences too.
Most characters in Attack on Titan are Westerners, and even if you combine all the non-white main characters, there are fewer than 10, whereas all characters in Demon Slayer are Japanese, and the work itself has a very strong Japanese feel.
The setting of Attack on Titan is a fictional country in a fictional time period, but the setting of Demon Slayer is real 1910s Japan.
Demon Slayer has many comedic scenes (especially in the beginning), whereas Attack on Titan is quite serious.
Demon Slayer is serialized weekly, while Attack on Titan was serialized monthly.
Since Demon Slayer is a Shonen Jump series, it follows the classic tropes of shonen manga, but Attack on Titan was rejected by Jump and serialized in Shonen Magazine, so it doesn't feel particularly like a typical shonen manga.
In Attack on Titan, there are many multi-dimensional characters to the point where it's hard to distinguish good from evil between Paradis vs. Marley, and characters described as "absolute evil" are few; however, in Demon Slayer, Muzan and Doma are clearly absolute evil, and the distinction between the Demon Slayer Corps and Demons is clear.
The military corps the Attack on Titan characters belong to represents the nation, but the Demon Slayer Corps in Demon Slayer is an unofficial secret organization, and few people outside the corps appear.
Attack on Titan features at least two main countries and has a massive scale where the fate of the whole world is at stake, whereas Demon Slayer has a smaller scale, not even covering all of Japan. Just looking at the final bosses' goals: World Destruction vs. Living Long by Myself.
The author of Attack on Titan, Hajime Isayama, is quite visible in public, doing many interviews and appearing at official events unlike typical modern manga artists, but the author of Demon Slayer, Koyoharu Gotouge, has kept their identity private and effectively retired after the series ended.
In Demon Slayer, the main four (Tanjiro, Nezuko, Zenitsu, Inosuke) all survive until the end, and it concludes with a closed happy ending, but in Attack on Titan, the protagonist dies, complete peace doesn't seem to have truly arrived in the world, and since it ends in destruction in the far future, it can't be called a happy ending.
While romance isn't a huge part of either, the three main characters in Demon Slayer all end up with their partners by the end, with descendants continuing 100 years later, whereas the main couple in Attack on Titan does not end up together. In the first place, there aren't many official couples there.
Seeing this, I wonder if the author of Demon Slayer took some inspiration from Attack on Titan.
Could we say Demon Slayer has the commercial success and Attack on Titan has the artistic quality? Of course, Attack on Titan's commercial success is only relatively lower than Demon Slayer's; it is still an all-time massive hit.
I hope the Demon Slayer anime finishes soon. I heard the Infinity Castle arc Part 2 is coming out next year, and I can't wait to see it.