I assume you're familiar with the other side of this coin, right? All the pre-Christian myths and traditions that bear a "striking similarity" to the Jesus story (but came first).
Discussion
Yes, Mithras, Krishna, Tammuz, etc. The parallels are either tenuous or the mythology is ahistorical.
I can just as easily say: christians made sure their version of reality is historical.
No more ahistorical than Jesus mythology.
We have no evidence Christians made it into Norse Territory until hundreds of years after the story of Odin on the tree.
I don't think the mythology of any of those other gods is any more ahistorical than Jesus mythology. Much of Jesus story changed after he was gone also.
Dionysius was born to a god father and mortal mother dismembered and resurrected over 1000 years before Jesus was born.
These story points are good memes so they spread. Nothing magical about any of this, just story points that scratch the itches of the human brain just right. Peter Parker was resurrected after the Thanos snap. A future historian might argue that Spiderman was a more dominant god of our time than Jesus based on his bigger box office score.