It has never been debunked except by non-historian amateur apologists using google searches.
Richard Carrier details this in his peer-reviewed book and covers it briefly here:
Dying-and-Rising Gods: It's Pagan, Guys. Get Over It. • Richard Carrier
He includes the original source material to demonstrate they are before Jesus. There are 6 known pre-Christian dying/rising savior Gods.
We also know the Persian prophet predicted a virgin born world savior would come to save humanity, the dead would resurrect at the end of the world, God had an demonic enemy who was against mankind and this was around 1500BC. The Israelites mergered these ideas into their theology during the 2nd temple period when the Persians occupied them. This is detailed by Mary Boyce in her work on Zoroastrianism and OT Professor Fransesca Stravapopolou for start. This is all standard knowledge in academia.
There is excellent evidence that a Greek/Jewish scholar wrote the gospel, it's full of mythic literary devices has parallels to Homer, is full of parables and is written like fiction.
Christian scholarship now acknowledges Mark is the source gospel:
The Synoptic Problem | Bible.org
So Mark is the one to examine.
Scholar D. Macdonald has an entire book on the evidence that Mark was using Homer as a source.
Carrier has an article with dozens of examples and shows 5 other peer-reviewd papers from historians that write about Mark's use of Paul to create his story.:
Mark's Use of Paul's Epistles • Richard Carrier
There is a blog article using Carrier's work that goes over the mythic nature of Mark and his use of other books like Psalms in the OT. An example:
"Only a few verses later, we read about the rest of the crucifixion narrative and find a link (a literary source) with the Book of Psalms in the Old Testament (OT):
Mark 15.24: “They part his garments among them, casting lots upon them.”
Psalm 22:18: “They part my garments among them, and cast lots upon them.”
Mark 15.29-31: “And those who passed by blasphemed him, shaking their heads and saying, ‘…Save yourself…’ and mocked him, saying ‘He who saved others cannot save himself!’ ”
Psalm 22.7-8: “All those who see me mock me and give me lip, shaking their head, saying ‘He expected the lord to protect him, so let the lord save him if he likes.’ ”
Mark 15.34: “My God, my God, why have you forsaken me?”
Psalm 22.1: “My God, my God, why have you forsaken me?”
On top of these links, Mark also appears to have used
Psalm 69,
Amos 8.9, and some elements of
Isaiah 53,
Zechariah 9-14, and
Wisdom 2 as sources for his narratives. So we can see yet a few more elements of myth in the latter part of this Gospel, with Mark using other scriptural sources as needed for his story, whether to “fulfill” what he believed to be prophecy or for some other reason."
The Gospels as Allegorical Myth, Part I of 4: Mark
So to say there is "no evidence" or that this has been "debunked" is completely wrong. What it has been is hand waved off by apologists.
What's weird is the 1st century apologists and church fathers admitted Jesus was like all other savior gods but said he was the real one. Now it's pure denial?
Christian apologist Justin Martyr:
When we say…Jesus Christ…was produced without sexual union, and was crucified and died, and rose again, and ascended to heaven, we propound nothing new or different from what you believe regarding those whom you call Sons of God. [In fact]…if anybody objects that [Jesus] was crucified, this is in common with the sons of Zeus (as you call them) who suffered, as previously listed [
he listed Dionysus, Hercules, and Asclepius]. Since their fatal sufferings are all narrated as not similar but different, so his unique passion should not seem to be any worse