Ah, I didn't wanna give the impression of completely ordinary so as to be a character from Dostoevsky's novels, but I guess how I wrote it can easily take the topic there. Just wanted to make the distinction between "you are someone special's descendant, albeit without yours' or viewers' knowledge till the story ends" vs "you are someone special only through your efforts, even among the specialty group of ninjas, heroes, devil fruit users etc." The first one has been pretty much trodden with either last minute revelations justifying huge power-ups, or setting the stage for the plot armor of the protagonists.

I'd argue that the will of ancestors is different, and even their effect on Luffy's development is rather through direct action than just being related by blood. Without Dragon directly interfering, Buggy would have got Luffy in Loguetown. "Strong blood" was never something openly used in One Piece before, even more it was pretty much criticized through some villains like Axe-hand Morgan's fascist ideology and the showcases of Celestial Dragons.

The illusion of re-emerging endurance through hardships all over again just thanks to willpower is just as a basic, and as a tired trope for plot as the use of ancestry, but it can nevertheless result in a good variety of situations like the post-Shabody separate training arc, and is a much more comfortable aspect to cheer for a protagonist through.

Having the ancient and most powerful spirit emerge through the protagonist to beat up the bad guys is pretty much against how Luffy's efforts are portrayed. Yes, Luffy does not acknowledge such a thing and plays the usual fool to not understand it, but for all intents and purposes, except for one to subvert later for a possible plot-twist, Luffy is regarded as Nika by the other characters and the audience. In my opinion, Luffy should have been rejecting such a thing as reincarnation or even personification of someone else outright so as to assert the quality, fun, and morals of his own efforts than to utilize ancient bloodline powers, like rejecting Raleigh's offer for the explanation of One Piece and being played favourites as well as being deprived of the fun of overcoming things by oneself.

Inherited will being a culture, thought structure, morals, or aspirations vs being some ancient person's spiritual being has been pretty distinct for me in One Piece till about Nika exposè.

It is a taste issue, and as far I can see you try to help out with the reframing the problem I have to resolve it, and I thank you for that.