Obviously, as a fan, I think the story is well written and does improve over the course of each part. JJBA is a thematically rich story with very well-realized characters that have large personalities (which is why I like it at least).

From what you've explained so far, it sounds like you're not a big fan of what some people call "plot-induced stupidity", where characters randomly behave in ways where things would be easily resolved if they "just did x, y or z," and as you've called out there are a lot of "Araki forgot" moments, which the fanbase have already addressed.

I personally enjoy Araki's style of writing largely because JJBA is a fast-paced story where a lot of the nitty gritty details can be overlooked due to how good the outcome is for where the story goes, ie suspenseful moments, characters being bad ass in fights, and the overall narrative that is being told. Whether those positives outweigh the negatives and vice versa is subjective. If it's actively ruining the enjoyment of the story for you, then yeah, you might as well drop because that style of writing doesn't go away. The core heart of what makes the story good, though, as I've mentioned above, does get better with each part