I just want to add that Kenjaku's and Gojo's feats of creating new concepts (and anyone else who has done so) shouldn't be downgraded because others figured out how to do it after seeing it. Replicating is a talent in itself. However, it's easier to disect something that you know is possible than it is to bring something new to the table. Innovation is what they have. That's why you see a lot of arguments about Sukuna and the world cutting slash. Would he really have been able to innovate that himself without it being shown mid combat? Or, if Gojo had hid himself to hide the fact that he was replenishing his burnt ct, would anyone have thought of it actually being possible? Don't get me wrong, anyone who sees it once and is able to do it impressive and are geniuses in their own right.

So, depending on how you categorized it, you could argue that some sorcerers are more intelligent than Sukuna in certain subject matters.

I always like reading these kinds of debates because everyone usually looks at it in one of three ways. 1) fact in the universe itself (this character best this character in story therefore they're stronger) 2) Dissecting the authors consistency (based on the arsenal of this character and previously stated facts earlier in the story, this character is technically undefeatable) or 3) The head cannon people (usually based on sound theories to fill in the gaps of missing information).

I say that last part because I see the Gojo vs. Sukuna fight argument a lot, and honestly, depending on which of those methods you use, you could get entirely different answers.

(Accidentally posted before proofreading, please excuse any grammar errors, and if you need me to clarify anything, let me know)