Christians usually accept many ancient writings as history books, but not inspired as infallible scripture. But, even as history books, they may contain legitimate prophecies that were given to various people of God.... all the way back to Adam.
From the beginning, Christians used the New Testament as their ONLY guide. Even the OT, while viewed as the word of God with valuable background information, was not in the same class as NT apostolic writings. Why? Simple. Christianity is a single event faith. Jesus rose from the dead. And that supersedes everything else.
Books like Enoch were viewed as history books by the early church leaders and worthy of study, but were generally not viewed as the infallible word of God. - Just a good history book for reference.
Here is a brief discussion of the book of Enoch from scholar Ken Johnson that is interesting.
https://www.youtube.com/watch?v=VaDfq3nEp9Y&t=371s&ab_channel=ProphecyWatchers