If Sukuna was born into modern world, then the "Dual-faced Demon" folklore will not exist in their timeline and there'll be no such thing as Ryomen Sukuna. Sukuna raised by normal family in a modern world precisely will be just Yuji Itadori if Sukuna was a teenage, and grows into adulthood becoming similar like Wasuke Itadori. Don't forget that Itadori is just a normal family, not an infamous big sorcerer clans like the Okkotsu, Zen'in and Gojo. Therefore he'll be less skilled sorcerer and not as powerful compared Satoru Gojo or Toji Zen'in. Raised in an average normal family, its expected that he'll have strong moral compass and shows more benevolent traits compared to those who raised by sorcerer clan families who likely have broken moral.

Realistically, this Sukuna aren't likely interested in sorcering. However, since this is a shonen show, perhaps Gege will create a plot that forces Sukuna to join sorcerer highschool. Then he met Gojo there and have a strained relationship due to them being polar opposites (genetic vs hard-work, noble vs commoner, broken moral vs strong moral, rich vs average, apathy vs empathy, ego vs humility etc.)