That’s certainly the view of the majority of academics and as with much that happened over two thousand years ago it’s difficult to prove anything one way or the other. The only first century historical references to Christ outside the New Testament works are from Josephus and Tacitus, not without controversy.There was NO Daniel.. Danel was a popular hero among the north coast Canaanites.. The Hebrews borrowed him and just kept adding to the story over a period of 500 years.
The Bible stories are wonderful fiction.. and the story of the Jews is far more remarkable, heroic, complicated and amazing than anything written in the OT or the NT.
The best arguments against Daniel is the impossibility of predicting future events along with the absence of Daniel from early versions of the Hebrew Bible. They are compelling arguments but the existence of the prophet Daniel can not be definitively excluded for one who believes in God and His Prophets.