The very worst thing about JJK.

the creator, Gege Akutami, intentionally designed the narrative to prioritize constant, breakneck battle pacing over traditional worldbuilding and slow-burn character development which to me its weakest aspect. This leaves me confused when it comes to new techniques/abilities or newly introduced characters (why should I care about their lives or deaths).

additionally the curse energy which ( Gege Akutami has openly admitted that the Cursed Energy system in Jujutsu Kaisen is heavily inspired by Yoshihiro Togashi's Nen system from Hunter x Hunter ) did not take enough time to be taught to us or new users like Itadori to properly develop.

Togashi used the Nen system starting in the Heaven's Arc (third arc of the series) with small hints and foreshadowing in prior arcs he kept developing the system (for the readers and the new learners of the system).

I dunno what's up with modern authors and their tendency to speed run writing... From what I hear many authors choose short format for their story but this hurts the pacing and development (both for the world and characters.)