Their is no concrete evidence the Jesus was a real person outside the bible. There is no real evidence he didn’t exist either. Proclamations of positive proof either way can be defined as conspiracy theories.
Faith is not proof. Constantine was a real person. He really did impose Christianity on the Roman Empire. He’s long dead so we have no way of asking him what his motives were.
The basic New Testament story line predates Christianity by thousands of years. That’s not a conspiracy theory. It’s an archaeological fact about as solid as you can get. You might as well claim the earth is only 6,000 years old and deny the evidence for evolution.
This iitem should not be on your list.