You forget, anotatedbookofmormon, that there
IS physical evidence of the great destruction!
How could Joseph Smith have known that archaeologists would someday find one of the "great cities" that the Lord "cast into the sea." Today it's called Samabaj and it lies beneath the waters of Lake Atitlan in Guatemala. You can read about it here:
https://knowhy.bookofmormoncentral.org/ ... nt-america(apologist version) and here:
https://unesdoc.unesco.org/ark:/48223/pf0000232917_eng (UNESCO version)
Ok, so it wasn't cast into the sea, it's in an inland lake,
And it wasn't a great city. It was a small village,
And it didn't sink suddenly in a great continent-wide disaster, more likely settled beneath the water due to tremors because it sits at the base of an active volcano,
And it was occupied until about 3 centuries after the great BoM destruction...
...but all in all I'd call it pretty solid evidence that there were many large cities cast into the sea on the same day, wouldn't you agree? Close enough, anyway!
And what about Joya de Ceren? BoM apologists have used that as evidence of the great cities that were "buried up in the depths of the earth."
Ceren was also a small village. It
WAS covered by volcanic ash but that happened about 600 years too late. And it was buried slowly enough that everybody had time to get out.
It seems that there are "fact" facts and "faith" facts, and we must be careful to never get the two confused.