Who's ignoring scholarship now? Scholarship suggests they're single sourced and written decades post Crucifixion.
And that's why they are identical to each other!
Even if we assume for the sake of argument that the Synoptic Gospels have a common source, what do you do with John?
Another point: my father fought in WWII, over 50 years ago. Recently he gave an account of the Italian campaign to my daughter for a history class. That's "decades post" WWII - five whole decades. Does that invalidate his account? It seems likely that the memories of those who knew Jesus are as good or better than my dad's recall (which is remarkably detailed.)
In the case of the Gospels, you have multiple sources, varying with their own individual recollections but confirming the basic facts of what occurred. You would expect accounts to be similar (but not identical) given that they are recounting the same story. And they are. As C.S. Lewis says, either the Evangelists anticipated the modern school of "realistic fiction" by about 1900 years, or they were telling the truth.
Actually, scholarship suggests the Gospels were written within a few years of the Crucifixion; and that the only book written "decades" after is Revelation (and possibly the epistles of John).
For example, the destruction of Jerusalem and the Temple in AD 70 would be impossible to ignore, and references to such a monumental event would have found their way into any biblical record. Yet, not even a hint can be found in any Gospel or epistle.