They are not. According to scholarship the gospels were gathered together sometime in the 2nd century and named. They all used an unusual title marker in Greek called "Kata" which basically means "as told to me by". So Mark is called "As told to me by Mark".
Even the Wiki entry on the gospels reflects that fact that they are anonymous:
"Despite the traditional ascriptions all four are anonymous, and none were written by eyewitnesses.
[13] Like the rest of the
New Testament, they were written in Greek"
Gospel - Wikipedia
But if you want to hear it from an actual PhD biblical historian go to 4:06:
We also know Mark was first - "The
Gospel of Mark probably dates from c. AD 66–70,"
and the other 3 were copied from Mark. This is known because there are literally pages and pages or verbatim Greek among all 4 gospels. Each gospel then goes off and creates different versions of the story. But there is far too much in verbatim for that to be a coincidence. They either used Mark as a source of there was a "Q" - common source gospel.
No it isn't amazing at all. Is it amazing there are millions of Mormons? Or that millions of people (hundreds of millions, possibly billions) of people believe Roswell was an actual ufo crash? Or that there are billions of Hindu?
It sounds like you are going for an argument to popular appeal but that doesn't work because besides obvious reasons before becoming law in Rome Christianity was only 5% of the population.
Then it became a law and was enforced through evangelism and militant enforcement. This is well known, No one has ever made beliefs in Roswell and alien abductions law yet the majority of people in the U.S. believe there is a government cover-up of crashed aliens.
I witnessed people believing in religion with zero evidence firsthand, and they did it because their parents did it and so on. It's not hard to see that people believe supernatural things without evidence and that it isn't a demonstration of it's truth.
If you go by religious population as a marker for truth then Muslims must currently be more true:
"Studies in the 21st century show that, in terms of percentage and worldwide spread,
Islam is the fastest-growing major religion in the world."
Growth of religion - Wikipedia
But what matters to truth is what does scholarship say? The general public believes in haunted houses and big foot. Are historians 100% convinced of the historical accuracy of the gospels? No, almost the entire historicity field considers the supernatural aspects to be myth.
"
Historicity of Jesus - Wikipedia
"The historical reliability of the gospels refers to the reliability and historic character of the
four New Testament gospels as historical documents. Little in the four
canonical gospels is considered to be historically reliable."
By modern re-telling I mean this idea that satan is this evil force who is completely against god and god's mortal enemy and similar.
In the earlier myths Satan worked for and with God to do his evil bidding. Like a hit man.
There is this more modern idea that satan is tempting people and is at odds with god and all this.
Well god used him as a super villian. So his acts were encouraged by god?
"In
2 Samuel 24, Yahweh sends the "Angel of Yahweh" to inflict a plague against Israel for three days,
killing 70,000 people as punishment for
David having taken a census without his approval.
1 Chronicles 21:1 repeats this story, but replaces the "Angel of Yahweh" with an entity referred to as "a satan".
"
Numbers 22:22, which describes the
Angel of Yahweh confronting
Balaam on his donkey: "Balaam's departure aroused the wrath of
Elohim, and the Angel of Yahweh stood in the road as a satan against him."
In
1 Samuel 16:14-23 Yahweh sends a "troubling spirit" to torment King
Saul as a mechanism to ingratiate David with the king. In
1 Kings 22:19-25, the prophet
Micaiah describes to King
Ahab a vision of Yahweh sitting on his throne surrounded by the
Host of Heaven. Yahweh asks the Host which of them will lead Ahab astray. A "spirit", whose name is not specified, but who is analogous to the satan, volunteers to be "a Lying Spirit in the mouth of all his Prophets".
"
Job 1:6-8 Yahweh asks, "Have you considered My servant Job?" The satan replies by urging Yahweh to let him torture Job, promising that Job will abandon his faith at the first tribulation. Yahweh consents; the satan destroys Job's servants and flocks, yet Job refuses to condemn Yahweh.The first scene repeats itself, with the satan presenting himself to Yahweh alongside the other "sons of God". Yahweh points out Job's continued faithfulness, to which the satan insists that more testing is necessary; Yahweh once again gives him permission to test Job."
Zechariah 3:1-7 ...on trial with Yahweh as the judge and the satan standing as the
prosecutor.