It’s really not that difficult to see who adds to scripture. Mormons, Muslims, and Catholics are the ones who add to scripture to come up with their religions.
Your thought process here is irrational; Mormons added the Book of Mormon to the Canon to make their own, check; Muslims are not Christians and did not add to scripture, they created their own book; fail, Catholics defined and preserved the Canon that you rely on; both Catholics and Protestants value the Early Fathers for context and history, neither include them in the Canon, which is why I ask where you learned this ? It sounds like a separatist sect or cult to me.
You still did not answer the question about Enoch, Moses, and Elijah.