Why were the books of Enoch not included in the Holy Bible?

I'm not sure what you mean exactly. The only book which is Holy to Christians is the Bible. Though different translations have been produced, this only changes the manner of speaking and language used.

Nothing of the base content has been changed in a very long time.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.