Of course that answer is incredibly vacuous. We have so few written records left behind we can hardly believe the Western Roman Empire ever existed either.
The gospels were written during the lifetimes of eyewitnesses who would have had a reason to and could have provided a refutation of the life and works of Jesus.
Or Shakespeare for that matter. There are no extant original copies of his works. That’s like recent stuff. You go back to Euclid and those people and you can’t prove they existed either. But with Yashua, there are outside evidence He existed, in Israel, at that time.
I see evidence around the world that Jesus existed; the pagan Romans gave us as good a record as anyone else.
Anyone who doubts the existence of Jesus Christ (not what He was, but that He existed) has ended any intelligent conversation before it even had a chance.