I am not trying to validate Enoch here.
I am pointing out even from Jude's few verses, it's just quotes. It could be from either oral/written materials of that time. But nevertheless, whatever Isaiah, Jeremiah, Daniel, the minor prophets, Matthew, Mark, Luke, James, Paul's Epistles, Peter,, Jude, Revelation quote of Enoch is from a true source. Whether that source was oral or written.
Now, what we have today called the Book of Enoch, in my opinion, it's been [added] to what they had back then. Therefore, it is not inspired.