Ballsy of you to say that. I’d like to know what proof you have of that.
Sure. Total lack of contemporary evidence, lack of all relics from his life, the inability of anyone to keep basic biographical details about his life straight, clear and obvious plagiarism from texts in wide circulation at the time, lack of a dynasty, and easier explanations for the scarce data that we have.
You could write Paul’s letters completely from just being told 2 things about Jesus and being familiar with Jewish and Greek writings. You could write the entire gospel of Mark with the letters and again some familiarity with the writings of the time. Matthew adds almost nothing. Luke-Acts just adds stuff about Paul.
Want the Euchrist? Guess what eating your god was a common mystery cult practice. Want a dead leader? All over Judaism start with the Maccabees. Want the last supper? Common fiction trope at the time. Want the Tomb? Again already in fiction. Feeding the multitudes and healing the sick? Easy, Elijiah.
That one does not have the right to basic sexuality, property, and what they say.
Being serious? All that stuff about giving up your property to charity, ripping your eye out instead of looking with lust, condemning people for not saying that he was lord?