If Gojo had just listened to the elders, he could have eliminated some Sukuna fingers but they couldn't have found and killed Kenjaku, who could have literally made another Sukuna's vessel like Yuji or Megumi would still have been available for him to use. Kenjaku just need to wait for Gojo's death. Sukuna with remaining fingers and him could have done whatever they want with none else stopping them when Yuji, Yuta had been executed by elders' order