Reasons Why the Septuagint is bad & was not quoted by Jesus, the Apostles, disciples, or Old Testament Prophets:

1) The Septuagint has the Apocrypha, which pushes numerous heresies, works salvationism, weird events, lies, and multiple, various contradictions.

2) Jesus mentioned the jot (which is a Hebrew letter) and the tittle (which is a Hebrew character) said "till heaven and earth pass, one jot or tittle shall not pass from the law, til all be fulfilled" (Matthew 5:17-18), BUT the Septuagint, written in Greek, does not contain the Hebrew jot or tittle and thus cannot be and is not the text that Jesus and the Apostles quoted in reference to the Old Testament.

3) Levities/tribe of Levi were the Old Testament's keepers and were Hebrews, not Greeks. The Levities, not Greeks, Egyptians, or Alexandrians, were commanded by God to keep the knowledge of the law of Moses
Deuteronomy 17:18 KJB
And it shall be, when he sitteth upon the throne of his kingdom, that he shall write him a copy of this law in a book out of that which is before the priests the Levites:

Malachi 2:4, 7 KJB
And ye shall know that I have sent this commandment unto you, that my covenant might be with Levi, saith the LORD of hosts.
For the priest's lips should keep knowledge, and they should seek the law at his mouth: for he is the messenger of the LORD of hosts.

4) The Roman Catholic Vatican claims they created the Septuagint in "Vatican Council II, the conciliar and post conciliar documents, Chapter VI, Page 763", which pushes the Septuagint's date forward to the 200-300s AD [not 100sAD], which is when Catholic heresies of baptismal regeneration, prayers for the dead (in Apocrypha which Septuagint contains & promotes), & unbiblical worship of saints & angels started occuring.

5) The Apocrypha goes against Proverbs 30:6 and Deuteronomy 4:2 by adding, inserting and mixing 14 books ("1 Esdras, 2 Esdras, Tobit, Judith, The rest of Esther, Wisdom, Ecclesiasticus, Baruch, Song of 3 Children, Susanna, Bel and the Dragon, Prayer of Manasseh, 1 Maccabees, & 2 Maccabees") throughout the whole Old Testament.

6) Jesus, in Luke 24:44 mentions the law of Moses, the prophets, and the psalms. The Hebrew Masoretic Text does have this division of books, but the Septugaint does not divide the Old Testament like that, due to mixing the Apocrypha with the Old Testament. Romans 3:1-2 KJB Romans 3:1-2 KJB is very clear on who the Old Testament was given to, and thus Jesus quoted Hebrew Masoretic Text/Old Testament, not Greek Septuagint
What advantage then hath the Jew?...unto them were committed the oracles of God.
The Hebrews would knew that the tribe of Levi watched over and guarded the Old Testament (Deuternomy 17:18, 31:25-26, Malachi 2:7), and to not give a copy of the Old Testament that they guarded up over to the same Egyptains that previously ensalved them 700-1,000 years prior.

7) God warned the Hebrews/Old Testament Israelities and the kings of Judah to not go down to Egypt for help (Isaiah 31:1-9). God even called Jesus out of Egypt (Matthew 2:14-15), and mentions Egypt negatively who enslaved the Old Testament Israelities (Exodus 1:9-14, Exodus 13:9) and later whose Alexandrians led to Stephen's death, as Alexandrians with bad doctrines from Egypt came, disputed, and bore falsely witness against Stephen, who was eventually stoned (Acts 6:8-15, 7:1-59).
Yet the Septuagint was made in and from Alexandria, Egypt by heretick Origen (who took the whole Bible as symbolic and disregarded a lot of Bible's doctrines) with his 6-column Hexapla that he made in the early to mid 200sAD.

8) The Septuagint's preface admits the Septuagint has "the unequal character of the version: some books show that the translators were by no means comptent to the task" (The Septuagint, Introduction, Page III LINK). So whoever wrote Septuagint was incomptent, not ready for the job & unprepared to write or make it.
Septuagint is terrible. It's an Egyptain, Gnostic text having no merit & needs to be ignored.
The self-contradictory junk "Letter of Aristeas" will be debunked tomorrow