Comparing Zenitsu and Bakugo, I feel like how characters react to someone with an over-the-top personality is just as important as their actual writing. (My Hero Academia, Demon Slayer)

Here's the thing, I got into MHA back in 2019, but as for Demon Slayer, I didn't get into it until this year. However, I was aware of a few things about Zenitsu through pop-cultural osmosis, like him being loud, cowardly and annoying, him only being able to fight while asleep and his crush on Nezuko.

So when I started watching the show, I thought I would dislike Zenitsu like so many others do, including on this sub, since the discussion on him is so negative.

And yet, he somehow ended up being better than I expected, at least in my opinion. And this is mainly because he does go over the top like Bakugo does but arguably funnier, and also because people are not glazing him or downplaying his behaviour like how Bakugo is treated in the early series.

Seriously, compare Tanjiro's initial irritation with Zenitsu's antics during their intro (because Zenitsu was clinging to a girl and insisting she marry him) to Izuku "Kacchan might scream bloody murder at me whenever he sees me, has told me to kill myself and will attack me for no reason but he is still my precious Kacchan and he should know about me having All Might's quirk before my mom does" Midoriya. The difference is night and day. Tanjiro only warms up to Zenitsu after his protection of Nezuko, so Tanjiro actually owes him.

Imagine a hero who is nice and kind but has a spine and is still capable of holding understandable dislike for people in cases. Horikoshi couldn't do that to save his life, since Izuku (after the first few chapters) feels virtually incapable of having any bad opinion of people that are not villains. Compare how Izuku seemingly doesn't care about Endeavor's abuses other than helping Shoto even though it is the first time he has heard of a hero being so awful, to Tanjiro actually still (mutually) disliking Sanemi for how badly their first encounter went, while he has gotten along with the other Hashira (except Obanai) who were about to kill him and Nezuko earlier.

Back to Zenitsu, in general people don't seem to like him very much, like Tengen being annoyed with him and the girls in the Butterfly mansion thinking he's a bit insufferable. Basically all of his worst freakouts are accompanied by appropriately irritated characters, including a literal kid calling out how pathetic he was in the mansion. Even after Tanjiro befriended him, Tanjiro yelled at him during his infamously perverted freakout during the rehab training arc. Odd how Zenitsu actually told Tanjiro to commit seppuku and it was actually funny imo because the series actually made it over the top and fit his insufferable behaviour rather than take it seriously then pretend it never happened.

The thing is that the subtext of Katsuki's bullying having seriously messed up Deku's self-confidence for years on end inherently undermines any attempt from Deku to glaze Bakugo and making it seem like it's a healthy rivalry. My biggest issue with Bakugo is not the s**cide-bait scene, but rather the general trend of Bakugo praise and denial/downplay of his most needlessly aggressive antics that undermined his redemption.

I don't think Demon Slayer is perfect in this regard and I am sure others will point out things like his creepy affection for Nezuko being overlooked, but the thing is that he is constantly mocked and humiliated for it. One of his biggest oofs is when he overreacts to Nezuko >!talking in the daylight only for her to call him Inosuke!<. The other girls were understandably weirded out by this and Aoi actually tried to get Zenitsu off of Nezuko at the time. In fact he can only get with Nezuko >!after her becoming a human again by fixing up his behaviour!<.

Ultimately, the difference between both characters is that one actually benefits from a writer that is more willing to embrace how cringy and awful the character is, so there's less dissonance between what the author and reader feel.