I think you’ll find pretty much all secular historians of the time and place will agree that there was personall probably an itinerant preacher by the name of Joshua going around in the area who was baptized by John, got in trouble with the local authorities, and got himself executed, but his followers eventually regrouped and built myths around him.

The gospels themselves, including the ones that didn’t make the cut in the Council of Rome, are a form of documentation, and Jesus is independently attested a several other times withina century of his death and not always kindly. It’s pretty decent documentation for a non-elite of that era, though.

Anyone who claims much more than that likely is shilling for Christianity, but it’s wishful or even conspiratorial thinking to insist that Jesus was completely made up. Better to attack the notion of his being divine, because that actually is sky-daddy nonsense.