@Ageless_Bum:
I saw the heritage revelations in several of the mentioned series completely differently.
For Naruto, he didn't get the revelation of his great heritage until he had already achieved greatness on his own. His heritage revelation was more of the prize for his hard work than arsepull power up.
That in turn reshapes all of Naruto's hard work in hindsight into seeming like it was at least partially due to having the right genetic potential and nepotism. Especially after learning that the Uzumaki clan specializes in sealing things, people mocking Naruto for being an orphan that has no potential to become anything great but turning out to be the fourth Hokage's son, Neji's speech about destiny during the Chunin Exams, everything about Rock Lee's conflicts, Naruto's unnaturally large chakra reserves even discounting the Nine Tails, Naruto being a chosen one in a prophecy that we've known at least since prior to beating Pain and Jiraiya's probably knew forever, and Naruto being a reincarnation of the literal God of Chakra.
Even if you can still argue that Naruto got all of his power through hard work and never relied on any of these supposed advantages, the sheer amount of coincidences here still strongly dilute how we perceive Naruto's original internal conflict and themes to an almost hypocritical level for the average person.
The revelation that Luffy is Dragon's son, Garp's grandson, and Ace's brother didn't do luffy any favors. He now has more people who want him dead for it. You could make the argument that he now only looks strong because of his lineage, but characters like Zorro prove that lineage has nothing to do with strength and Sabo is rediculously strong but his parents are/were frightened little babies.
I agree with this, but it's mainly not a problem because Luffy's appeal and conflicts were never emphasized as him being an everyman or failure like Deku and Naruto. He was a weird absurdly strong boy from the start who always seems to have luck on his side and almost always never cares about the grander scheme of an arc or the world's lore.
Although I could still care less for the straw hat being special since I always liked it being valuable purely on a personal level, not because it used to belong to the Pirate King or Void Century or whatever. Although that can still be kept intact since I doubt Luffy will ever care about his straw hat anymore than fulfilling his promise to Shanks.
Urameshi's power up at the end of Yu-Yu-Hakusho was pure arse-pull though. He didn't want it, so accepting it was a bit of a character arc, but he really did nothing to obtain it.
Indeed.
If Deku suddenly became outed as the son of a hero line, or even a single great hero father, I do not think it would cheapen him in any way. He didn't become a hero with his mom or dad's quirks (though I have a theory that they will manifest and mix with OFA eventually to increase his abilities). He did just get power handed to him on a plate, but he has had to work to learn how to use it, so it didn't feel as cheap.
In the context of this situation, people are suggesting that his lineage might make him be able to perceive One for All's previous incarnations and might give him more abilities.
I share Triple C's opinion in not seeing that at all, but if that is the case, yes, it does cheapen Deku. That would mean he already has an advantage over All-Might, another One for All user who seems to have had no Quirk in the first place (I don't think we know that for sure yet…?). It makes Deku look like he was always special on a biological level. Even though Deku's backstory conflict, literally the first page of My Hero Academia as a whole, was literally introduced with the words:
"People...
...Are not born equal."
Deku's appeal is supposed to be in how he was born in the bottom rung of life. A nobody who is born without a Quirk that still wanted to be a hero, realizes that he does need a Quirk to become a hero, is still willing to risk his life by powerlessly helping a friend in danger, gets a chance to get a Quirk by heroically inspiring his mentor and fiercely exercising his body, then needing to train several times harder just to even use that Quirk in mediocre portions as he gradually learns to master it at the cost of severe bodily harm, and also has to learn how to properly become a hero on a technical and ethical level.
And keep in mind that throughout all of this, Bakugo got praised by all of his peers mainly because of having a flashy Quirk to begin with even though he made his hostage rescue situation even worse by blasting explosions everywhere. While I'm sure that Bakugo has always trained on physical and mental levels on top of his talent, he and everyone else around him before entering U.A. pretty much thought he was born perfect. Until U.A. knocked him off his high horse and he started respecting other people giving their best efforts even if they lost to him.
Even if Deku made it up to this point by his own effort, getting a bonus genetic ability now sets a sign post saying that anybody with One for All would only get this far unless they were Deku. Along with recontextualizing Deku's backstory as people just not realizing that Deku had cool special genes all along like Bakugo did but in a different way.