We don't fucking need Sanji to prove Judge that a regular human can be stronger than his modified kids anyway, there's the Garps and the Shanks of this world to showcase that clearly
Yes, WE don't need proof for that. Judge does. Despite having people like Roger, Garp etc. he stil modified his children. He wouldn't do that if he would believe they just simply could get this strong without it.
Judge thinks emotions make you weak and Sanji's way of life where he cares for others is a sign of weakness. If Sanji proves him that by living like that he can become way stronger than his brothers and even his modifications end up outshining theirs as result of him amping them up further with his emotions, then it's Judge's complete loss when it comes to him contesting Sanji's way of life.
Emotions AND the lack of Sanji's modifications is what makes Judge think Sanji is weak. He literaly mentioned it at the end of WCI and you have Reiju who is modified, but kept her emotions. Yet he doesn't consider her weak, weird right?.
Dude do you even read what i write?
Sanji reaching new hights because of this ill intervention will not show how wrong Judge was. He might change his thought about Emotions, but he will not change his thought about modifying humans, since it made Sanji reach those hights. He will see it as a succes and not be like ''Oh Sanji you were right! I am sorry, all the experiments and interventions i did on humans were wrong!''...
Modifying humans is the same as pumping them full with enhancing drugs. That shit is wrong and it doesn't matter if you use your enhanced power to do good things or whatever.
Judge literaly makes experiments on his unborn children, people on this forum: ''But Sanji has emotions and does good things! This will show Judge that his experiments were wrong!''...
Judge: ''Sanji, i see it now! You were right! Emotions are a powerfull weapon. Next time when i modify my unborn children, i will make sure they will keep their emotions!''