Books that were written by apostles (or their assistants) and represented Jesus teachings were considered bible. Some other books were kept for reference. Books not written by the apostles (or assistants) were not chosen to go in the Christian Bible. Some people like the non “apostolic” books in their bibles and some don’t. But all denominations only consider the apostolic books to be proper scripture.

The Old Testament canon was already well established by Jesus time. Nothing removed from that. The New Testament includes writings by the Apostles (or their scribes - Mark writing for Peter, and Luke writing for Paul), as well as James and Jude who were younger brothers of Jesus. Everything else, whether in the apocrypha or lost to time, were deemed unreliable, maybe even heretical. No conspiracy involved, just careful consideration of to preserve sacred writings and discard the chaff.

They didn’t remove them. The Bible wasn’t compiled until the council of Nicea. And they only included what the elders of the churches considered reliable and inspired. There were heretical teachings and books like the gnostic gospels (gospel of Thomas, gospel of Mary and others) which were attempts by some sects attempting to deceive the early church. Read the book of Jude to see what he thought of such men. The Apocrypha are included in some Bibles, but are not considered inspired.

Here’s an article that provides more clarity on what Constantine did and didn’t do. https://www.gotquestions.org/Constantine-Bible.html

i just started reading the book of enoch it is sooooo goood it's answered allot of questions i've had and opened a lot more

They weren't inspired by God or the Holy Spirit

Because the Bible was canonized by the Catholic Church, many things in those other books don’t go with the Catholic churches beliefs. There are 33 books talked about in the Bible that are not present. The Catholic Church owns those scriptures in those books.

To please the rulers

There WAS NO Christian Bible before several groups began to try assemble the best of all the writings that existed a century or two after Christ. These groups varied in how selective they were. The Ethiopian Bible included 88, 84, or 81 depending on exactly which version you pick. The Catholics chose 72 or 73 depending on whether you combine Jeremiah and Lamentations. The Protestant Bible was the most selective at 66. Read Tobit or Sirach and you can see they seem a little “off”.