I guess I don't care about the end goal. Like, sure, we knew Dio was the end goal for all of Stardust Crusaders, but Dio still seemed utterly irrelevant for the entire middle section of the story between the first and last few episodes. In a way it's worse, because the show is taunting you with the promise of Dio - who you already know to be a cool villain from part one - but blueballs you for nigh on fifty episodes with way less compelling fights against fodder enemies that exist for the sake of being fodder. I also don't think the characters were all that interesting. Kakyoin and Avdol bring almost nothing to the table, for instance, which really hurts the story because it's hard to be all that invested in them when they die. And so many of the fights, especially in the first half, are just so boring.
So far, the cast of Diamond is Unbreakable is much more funny and enjoyable to be around than the stoic hardasses of SC, and while the fights are fodder, sure, they're done in much more interesting and enjoyable ways. Rather than "here's some fodder enemy that doesn't matter just to kill time between now and Dio", it's "here's some crazy girl who's way too obsessed with Koichi with a crazy hair Stand!" and "here's some Italian chef that Josuke thinks is suspicious but actually he's just making great food that heals his patrons!" It gives the enemies nice characterizations and tells these more personal, smaller stories.
tl;dr, it's about the journey, not the destination, and DiU makes the journey way more enjoyable than SC ever did.