There is an old adage that "truth stands the test of time." Or conversely, the passage of time is the greatest enemy of fallacy.
Myths can survive for a season, but time and logic will eventually eviscerate them. Whether conceding that Thor doesn't make thunder, the world is not flat or that polygamy and prejudice against blacks are bad ideas, the longer an institution holds fast to falsehoods, the dumber it looks.
Another fallacy is now unraveling; namely, that homosexuality is an unnatural and heinous sin. This myth is not standing the test of time.