Back on topic...
The so called ‘missing’ books are interesting because there is no MSS evidence that most ever existed, a couple of them are currently in the cannon under different names according to some scholars, and just because a book is listed does not mean it was ever considered to be scripture, so the argument that the Bible is ‘incomplete’ doesn’t hold water.
Well, they probably existed at one time, however, that still doesn’t require them to be in the canon of scripture. Paul quoted a greek poem at mars hill - does that belong in the canon (resounding NO). Those other books were not protected by God to go forward as scripture. Many of them were more secular in content and use - so no need for them. Enoch was put together over the course of 200-300 years - by people other than Enoch. Popular read - but not scripture.