The rational wiki seems to be reasonably well researched, and isn't committed to traditional interpretations, so their observations around the authorship of Mark (which basically provided the source material for the 'Matthew' and 'Luke' books)

From: https://rationalwiki.org/wiki/Gospel_of_Mark

> Although written anonymously and in third-person, the author of the Gospel of Mark is believed, per Christian tradition, to be Mark, the interpreter of Peter the Apostle. However, this tradition should be taken with a grain of salt, for Papias, the originator of this tradition, was, by far, no scholar. It has been suggested that the book was originally intended as fiction and further that its author understood the non-historicity of Jesus.

> The Gospel of Mark is considered the first of the gospels written because the only material it contains that is not contained in the Gospels of Matthew and Luke are a few insignificant details that anyone in his right mind would edit out. It can be dated to 67 CE by its apocalyptic Oliviet Discourse, for it mentions "wars and rumors of wars", a reference to the First Jewish Revolt, tells of the persecution of Christians under Nero, who died in the summer of 68 CE, tells the Judeans to "flee to the mountains", which would be stupid after the autumn of 67 CE, and, especially telling, prays that the flight of the Judeans may not be in the Winter. Documentation of these events sets the lower limit on the date of authorship at about 67 CE, but does not rule out the possibility that the gospel was actually written much later.

Actually, more specifically, I have a problem with:

> All that said, I see no problem with using a convenient designation to refer to a hypothetical author.

And that is -- it's not terribly convenient if it distracts the under-informed reader about the provenance of the source material.

In this specific case there's the insinuation of authority by proximity / familiarity.

While it's a convenient designation, continuing to imply the author of the primary source of the new testament was someone we can identify gives it more credibility than attributing the story to an unknown source, or an amalgam of sources.

Compare and contrast, say, Greensleeves -- a piece that everyone in the UK and AU recognises as indicating soft-serve ice cream is in the area, where the composer / author 's actual identity is at best secondary -- attributing a work of fiction to a (likely wrongly) named author grants credence that may be inappropriate.