aqwsed12345 - Thanks for the research. JW's believe what they believe because it provides them with a time to enter and re-establish true Christianity. It fits their narrative.
In reality, they have metamorphed into something foreign from the scriptures they claim to be patterned after.
As for the Bible Canon, they support the work of early organizers who picked the writings that would be recognized (for the most part) as the authentic Bible canon.
I offer no opinions on whether some are illegitimate or missing. Having seen the blatant hypocrisy of WTC, I wonder if any organized religion can adequately represent the teachings of Christ.