So what you are saying is that any doctrine or dogma built on any assumption would be built on a myth. That would be correct. Even the Catholic Church admits there is no supporting evidence which places any thoughts about the matter in the area of hearsay and conjecture leading to myth. And that is where the CC finds itself today as it pertains to Mary.
No myth as I said before. There are writings from Early Church Fathers (which you choose not to believe.)
One example is that apostles were bi-located to her bedside as the Blessed Virgin Mary died.
I’m not asking you to believe it; I’m just saying there is a foundation of truth here — even though you might choose not to believe it.