Well genius, you might want to let authors in the OT, who mention the book of Jasher at least twice, know about that, and also Paul who writes in Timothy that ALL scripture/texts should be used to understand the Word - paraphrasing.
Kindly UNparaphase and give a source for your assertion.
It is not I who am example mental deficiency here (though i certainly am no genius) but you, who reasons that the mention in Scripture of a source as providing material means that all they say must be Scripture.
Thus, since Paul quoted from the Cretan poet Epimenides (Titus 1:12) and from the pagan poets Epimenides and Aratus in his speech at Athens (Acts 17:28) then all they said must be considered a wholly inspired Scripture.
As must the Book of the Wars of the Lord, (Numbers 21:14), the Book of Samuel the Seer, the Book of Nathan the Prophet, and the Book of Gad the Seer, (1 Chronicles 29:29) the Acts of Rehoboam and the Chronicles of the Kings of Judah, (1 Kings 14:29) and the book of Enoch. (Jude 1: 14-15) But which Scripture can include true statements from such, this does not mean they are wholly inspired Scripture.
And which includes books that God did not care to preserve, which appears to be the case with the book of Jasher. There is a book called “The Book of Jasher” today, although it is not the same book as mentioned in the Old Testament. It is an eighteenth-century forgery that alleges to be a translation of the “lost” Book of Jasher by Alcuin, an eighth-century English scholar.
There is also a more recent book titled “The Book of Jashar” by science fiction and fantasy writer Benjamin Rosenbaum. This book is a complete work of fiction. Another book by this same name, called by many “Pseudo-Jasher,” while written in Hebrew, is also not the “Book of Jasher” mentioned in Scripture. It is a book of Jewish legends from the creation to the conquest of Canaan under Joshua, but scholars hold that it did not exist before A.D. 1625. In addition, there are several other theological works by Jewish rabbis and scholars called “Sefer ha Yashar,” but none of these claim to be the original Book of Jasher. https://www.gotquestions.org/book-of-Jasher.html
Moreover, the reason why there are "forgotten books" versus established ones is because, apart from conciliar decrees, both men and writings of God were established as being so essentially due to their unique heavenly qualities and attestation, complementary and in conflation with what already has been established. Which leaves others in the dust, except among a few eccentrics. Some contend that Eugene Swedenborg was of God and his writings were Scripture, and others that the books Enoch was, but both fail conflation with and are contrary to Scripture.
and also Paul who writes in Timothy that ALL scripture/texts should be used to understand the Word - paraphrasing.
And Paul never referenced Jasher or other books as Scripture which those who sat in the seat of Moses recognized as being established Scripture, and which he said were "wholly inspired of God," not partially.