If one looks at the evidence it becomes rather problematical. No contemporary witnesses. Non-Christian sources that wrote about what Christians believed but not really anything about Jesus himself.
It's sort of a false standard though, why would we expect contemporary sources for a poor, moderately popular preacher from a backwater like Nazareth? We don't have any eyewitness accounts for countless much higher profile historical figures and events that we don't consider to be purely mythical. Near-contemporary is actually considered a pretty decent historical standard.
The history is exactly as we would expect for Jesus the man: the movement only become visible when it gains a certain level of popularity. It's evidence against the accuracy of the Biblical narrative sure, but it's hardly surprising for Jesus the man.
That there were non-Christian sources writing about a rapidly growing community of believers across a large geographic area within a few decades of his purported lifetime is very strong evidence that the movement was built around a real person. Rapidly growing cults tend to be built around central figures, and I'm not aware of a single other examples of a movement built around a purely mythical figure who basically lived a normal human life (later turned into a hagiography) that emerged near-contemporaneously with his purported life. We don't start from an assumption that any person mentioned close to their life, but not during their life is equally likely to be a myth as real.
The Gospel narratives also make far more sense as being based around a historical figure than as pure fiction as he's a terrible fit for the messiah, and have to create convoluted backstories to explain the inconvenient detail that he was known to be from Nazareth, yet needed to be from Bethlehem.
Added to the fact that none of those hostile to Christians ever believed he was a pure fiction, and Romans would have had records of the people they crucified, a clear balance of probabilities emerges.
That no individual piece of evidence offers objective proof, doesn't mean that the overall evidence is equally likely to reflect a mythical figure as a real one.
Why do you think that these things are better explained by a mythical Jesus?