The JWs deny the divinity of Christ so they just changed the words in
the New World Translation to read:
"But with reference to the Son: 'God is your throne forever and ever.'" 1:8
Did Jesus die "by the grace of God" or "apart from God"? "There are good reasons for thinking that the latter ... was the
original reading of the Epistle to the Hebrews." [Bart Ehrman,
Misquoting Jesus, (2005), p.145] 2:9
"Our brother Timothy is set at liberty; with whom, if he come shortly, I will see you."
The author of Hebrews never claims to be (and wasn't) Paul, but he wants people to think that he was. And it worked.
That's why Hebrews is in the Bible. 13:23