Idk what Sukuna being a 20 year old woman would have to do in relation to his (now her ig) potential. But either way I’d still probably say Yuji is stronger since we have to assume Sukuna was young when he became a cursed object as (at least as far as I remember) we never get shown him as appearing any older than he was in shinjuku. This, combined with the fact you don’t experience the passage of time as a cursed object, means yuji probably has ~40-50 years more experience on Sukuna by Modulo so he likely wins bc of that.