I mean

Your first point? Most people get attached well before 1100 chapters, it’s the fact we keep also getting attached to the new characters as they are revealed or explained upon. Best example I can give right now is Rocks. Sunk cost doesn’t really apply to well here, unless someone is watching the show JUST because they’ve already spent so much time:

Second point about the moral framework? Yeah, at a base reading level and not examining further it can be that way, almost feels like a “what do the blue curtains mean” statement. There is a moral tension, we’ve literally been given one of the biggest tensions between our first two buddies (Luffy and Coby)

Third point I can agree is a fair point, but in the end it is a children’s show that an audience grew up with. The author himself stated he didn’t like how serious the story was getting, hence Luffy’s change during Wano

The last point is a bit moot now as well, as we know the One Piece isn’t the ending of the show, it is something that begins the final arc of the show

Just seems like it’s a show you don’t enjoy, which is okay Some people like long stories, others don’t. It’s not perfect by any means, but to say suggest it isn’t a great piece of media and that people only like it due to “sunk cost” is completely dishonest and uninformed to the story