Let me flip it around and ask you in what ways this Jewish Rabbi who you think probably existed resembles Jesus? How can you say he does when we know literally nothing about him? I didn't actually say that he bears no resemblance to Jesus in anyway, I was simply implying that we know nothing about him so for all we know he bears no resemblance to Jesus, and the onus is still on the believer to demonstrate a connection. Until a person can even be identified, this is going to remain a tall order. Maybe there was someone, maybe there wasn't, but when you're dealing with maybes, it's always best to err on the side of non-belief.
We know there were thousands of Jewish Rabbis around at the time in many sects, but we know very little about their life stories. What evidence is there for a Jewish Rabbi who was born in Bethlehem, had 12 disciples and was crucified in the 30s? Those are some of the earth-bound elements of Jesus's story and none of them have any evidence outside of the gospels to support their veracity; gospels which were written decades later by unknown authors. It's not extraordinary to claim that these events didn't happen. Jesus was probably based on many different Jewish Rabbis of the time, at best.
The convoluted gospel stories could well be based on disagreements rooted in the fact that although the stories are mythical, the motives behind the writers shifted over the decades, requiring earlier parts to be altered with convoluted additions, like the Bethlehem story. The origin doesn't have to have been genuine for that to be the case.