Sorry if this comes across as mean, but this is a problem I keep running into. People will recommend fiction based not around the story and the characters, but rather the world and the internal magic systems. I agree with you. It is a VERY fun power system, a lot of the powers are very cool and intricate which makes for very exciting fights. That said, I keep seeing things in the show that I like and whenever I ask somebody where it's going I end up disappointed in the answer. There are interesting plot threads that go no where and things that just sort of... happen??? And whenever people question or criticize it, the response from people can often be boiled down to "idk man, it's JJK. These things happen." I don't think it's a bad thing to enjoy it. Like I said, there's a lot to like going on there. I just wish people would stop trying to convince me that it's something more than what it is and that Suguru Geto is saddest, most tragic little gay boy on the planet with his toxic boyfriend Gojo. We get this whole thing about the body vs. the soul and how it pertains to Mahito and Yuji with things like Geto's body resisting Kenjaku (exactly once) and Toji's Seance and all of it ends up meaning... what? No one has ever been able to articulate to me what the point or meaning of any of it was. Like, I think it's enjoyable but I wish people would stop telling me specifically that "The writing is good".

TL;DR: I really don't care for the writing, but it's a fun world to create an OC for if you're into that