Responses

No he isn't, he literally needed someone to show him to to beat gojo and his infinity, that's not just "trying to challenge theories", while yes he did have some hunch on how to beat gojos infinity he was never sure. And he wouldn't have achieved the same results wasn't it for mahoraga. So far, sukuna has had no feats other than his domain which would've "bypassed" infinity (and world cutting slash doesn't even count since he literally had to use raga to show him some sort of a way)
Gojo was actually right about him winning against sukuna
if sukuna didnt cheat and took megumis shikigami, gojo would've bitch slap that four arms across the globe amen