of mankind does not always mean it is referring to every single person on the planet or who has ever lived.
For example: “All the world“ does not mean all people even according to the dictionary.
https://dictionary.reverso.net/english-definition/for+all+the+world
James 3:7
”For every kind of beasts, and of birds, and of serpents, and of things in the sea, is tamed, and hath been tamed of
mankind:”
This truth in James 3:7 refers to all mankind in general. But do you think the word “mankind” is referring to every single person in mankind? No. Surely not. Not every person on the planet has engaged in the activity of taming animals.
For example: Romans 3 says
all have sinned and have come short of the glory of God. This is obviously not referring to Jesus. So Jesus is not a part of the “all” in Romans 3 because Jesus never sinned. There are several examples in the Bible of how the word “all” does not always mean “all” in the most strictest wooden literalistic sense.