I think it's helpful, when considering historicity as it relates to the stories in the Gospels, to think about what a believer or outsider view of, say, Mormonism might be if our only sources were written 2nd or 3rd hand, mostly by a very small number of believers, years to decades after the actual events.
In the case of Mormonism, we have tons of other sources from outside the faith, and the claims made by the faithful were largely recorded more-or-less as the supposed events were happening. Our view, and the religion itself, would likely be a ton different if our sources for all that were more like what we have for Jesus and the events of the Gospels. Plausibly, what survived might hardly have any basis in reality whatsoever.
In the case of Mormonism, we have tons of other sources from outside the faith, and the claims made by the faithful were largely recorded more-or-less as the supposed events were happening. Our view, and the religion itself, would likely be a ton different if our sources for all that were more like what we have for Jesus and the events of the Gospels. Plausibly, what survived might hardly have any basis in reality whatsoever.