Also Maccabees 2 was included in the Codex Sinaiticus which dates to the 4th century. Similarly Augustine and the Synod of Hippo in the 300s considered it as canon
on what basis do you reject it and yet accept other books as canon?
You then say More importantly, Maccabees is not written to believers in Christ. Both books predate Christ’s sacrifice Joe -- well, every Old Testament book predates Christ's sacrifice
Actually, "The theory that Jamnia finalised the canon, first proposed by Heinrich Graetz in 1871,[2] was popular for much of the 20th century. However, it was increasingly questioned from the 1960s onward, and the theory has been largely discredited."- https://en.wikipedia.org/wiki/Council_of_Jamnia
"There is no scholarly consensus as to when the Hebrew Bible canon was fixed: some scholars argue that the Jewish canon was fixed earlier by the Hasmonean dynasty (140 and c. 116 B.C.)." — https://en.wikipedia.org/wiki/Development_of_the_Hebrew_Bible_canon
Yet it is also a FACT - based on the internal testimony of the NT - that by the time of Christ an extensive body (canon) of writings had been established as wholly inspired-of-God and authoritative, which as a body were referred to as Scripture. Obviously the hearers knew what this referred to.
And thus it is also a fact that upon which prophetic and doctrinal foundation a group of itinerant preachers and Preacher established the NT church, in dissent from the magisterial stewards of Scripture, but who never contended against the inspired writings that these preachers invoked as the authoritative word of God ("Scripture," it is written," etc.).
And as is abundantly evidenced, the word of God/the Lord was normally written, even if sometimes first being spoken, and that as written, Scripture became the transcendent supreme standard for obedience and testing and establishing truth claims as the wholly Divinely inspired and assured, Word of God.
Remember that the Dead Sea Scrolls have other books in their canon
Which IIRC these were in a separate chamber, and it is quite obvious they their existence did not mean they were necessarily candidates for canonicity.
Also Maccabees 2 was included in the Codex Sinaiticus which dates to the 4th century.
And? all three codices [Vaticanus, Sinaiticus and Alexandrinus], according to Kenyon, were produced in Egypt, yet the contemporary Christian lists of the biblical books drawn up in Egypt by Athanasius and (very likely) pseudo-Athanasius are much more critical, excluding all apocryphal books from the canon, and putting them in a separate appendix. (Roger Beckwith, [Anglican priest, Oxford BD and Lambeth DD], The Old Testament Canon of the New Testament Church [Eerdmans 1986], p. 382, 383; Triablogue: The legendary Alexandrian canon)
Edward Earle Ellis attests,
“No two Septuagint codices contain the same apocrypha, and no uniform Septuagint ‘Bible’ was ever the subject of discussion in the patristic church. In view of these facts the Septuagint codices appear to have been originally intended more as service books than as a defined and normative canon of Scripture,” (E. E. Ellis, The Old Testament in Early Christianity [Baker 1992], 34-35.
And contrary to the presumption that the Septuagint contained all the apocryphal books at that time, for which there is no extant historical evidence. The earliest existing Greek manuscripts which contain some of them date from the 4th Century and are understood to have been placed therein by Christians.
Similarly Augustine and the Synod of Hippo in the 300s considered it as canon
And? Many other esteem men did not, and these councils were not ecumenical, leaving the door open to disagreement until after the death of Luther. Thus as even the Catholic Encyclopedia states as regards the Middle Ages,
In the Latin Church, all through the Middle Ages [5th century to the 15th century] we find evidence of hesitation about the character of the deuterocanonicals. There is a current friendly to them, another one distinctly unfavourable to their authority and sacredness, while wavering between the two are a number of writers whose veneration for these books is tempered by some perplexity as to their exact standing, and among those we note St. Thomas Aquinas. Few are found to unequivocally acknowledge their canonicity. (CATHOLIC ENCYCLOPEDIA: Canon of the Old Testament)
on what basis do you reject it and yet accept other books as canon?
On what basis did common souls correctly ascertain both men and writings as being of God before there was a RC church which presumed she was essential to assuredly know this?