my opinion is mark is writing post the destruction so gives jesus the extra gravitas of knowing the future as a divine being wouldMark is the first gospel that is ascribed to be around 70AD, mostly because of the destruction of the Jewish Temple during the war. I think Mark is likely before this though and his sources are even earlier.
Some scholars don’t like to put Mark before 70AD because it would mean Jesus predicted the fall of the temple, rather than the author of Mark knowing this fact post war and attributing the prediction to Jesus but to be frank, a war had been brewing for years between Jews and Romans and it wouldn’t have taken mystic meg to predict the romans would sack the temple.
there was obviously scripture relating to Jesus knocking about before 50-55AD as Paul referenced them in his letters telling his congregation to stop squabbling and to go back to the scripture and the letters are pretty solid in their dating to 50-55AD.
Paul’s letters are the oldest Christian manuscripts dated around 50-55AD but I think there is a chance that Mark, or more likely parts of Mark’s sources he copied, were written earlier… we just don’t have archeological evidence of that so cannot confirm.
I think it’s obvious the information was scatter gunned across the region over decades with scripture here and there about Jesus and oral tradition among generations too. I think the Gospels are just the 4 who put it all together with what they could find. Mark was likely much nearer than John, with Luke and Matthew in between.
just my opinion though but makes sense to me as the jesus of faith is a non starter in my world