Some fanbases are more rabid than others, it’s not only One Piece, Berserk and HxH, having the advantage of being old ass rarely discussed due to hiatus series nobody remembers the complaints they used to have, and attacking them would result in a backlash, those two would be other examples, while other fanbases, such as Naruto(only after it ended, when it was airing it had a strong following too, and you could never see people moaning about Rock Lee [another trash character, don’t delude yourselves, nothing would change if he were to beat any opponent, actually, it would make the entire setting dumb, and all the “noble” clans would look retarded for pursuing better genetic offsprings for centuries] at the time, and the infamous “coolest guy ever” line was even defended quite a lot before Boruto was on and the original fanbase moved on for the most part, Dragonball (many people self inserted as Gohan, and still do, so they wanked the Android saga and mocked Majin boo, also, TFS brought a new fanbase that saw the series under absurdist lenses, so it became very easy to mock several aspects of it) Bleach (kinda complicated, it was banned in several Countries due to violence, but was still able to get a fanbase larger than Berserk, and Kubo also loved to clown on fan favourites such as Hitsugaya, or Kenpachi in the final arc) are more willing to “take a beating”, making them easy targets for important people like Youtubers, who will then go on to shape the image of the average manga/anime reader/watcher. You’d have to do something completely heartbreaking to the fanbase, like the end of GoT or AoT to have “permission” to shatter the aura of “perfect illusion” they used to have.
One Piece with Wano, laughed at every notions the series had, while also destroying the agency of each characters in order to move the plot Oda wants, all in order to make the Strawhats easily progress to the end (you can pinpoint the start of it being the Raizou is fine scene), that’s not enough though, Luffy, Zoro, Sanji, Law and Kid are fan favourites, and their rise in power and notoriety vastly outshadow the bad writing and shoehorning regarding them, so at best, the fragments of truth regarding the current state of One Piece and its characters and plot will be found when a fan of something will try to slander another fan of something else, it’s probably the instant they have to be the most analytical about the manga, well, a part of, that is.